Certain things, with actors, you do not do. You do not admit, ever, you did not enjoy a performance. You do not, in questioning, say a Roy Rogers, sight for Gene Autry. And you do not, at home with Aunt Bluebell, the yenta with the search-and-destroy voice who peddles Scot Towels on TV ("Weigh it for yourself, honey") ever say that in viewing her and Mr. Whipple (his metier is toilet paper, you often wish to go for their respective throats.

A shudder, then, will pass over Aunt Bluebell, from the hem of her flowered Travel-Lite gown to her tousled gray hair; a look of pain as if her good-natured heart had been pierced by a cherub's tiny arrow.

"Oh," Aunt Bluebell will say then, "the Charmin guy. Don't say that. Don't compare me to him, please . . ."

Immediate warning noises come from the direction of Aunt Bluebell's omnipresent husband then, and Aunt Bluebell quickly modifies her tune.

"Of course," says Aunt Bluebell, "My schtick, I would say, is a soft sell. I would say. And nobody has ever said I annoy them. Ever. My appeal? I think I appeal to people because I'm likable. I'm an awfully nice lady. There's no bitchiness in me . . . well, let's face it."

This last she says with no self-consciousness, merely the assurance of someone stating the obvious, Aunt Bluebell - whose real name is Mae Questel - has, after all, made a career out of being the opposite of bitchy - of being adorable, of being comical, of being cute. Do you remember her as Barbra Streisand's plump meddlesome neighbor in "Funny Girl" (the movie version)? How could you resist such a face? What about Mae Questel as the mother who force-feeds her announcer's son his cough medicine in the Romilar commercial, wiping the medicine off his chin? As she says herself, that was one funny bit; wait, she'll get up and do it for you, you'll be the son.

Of course, her forte, as she says, was her voices, he mimicry.She's done over 1,900 cartoons. The longest, from 1931 to 1967, was Olive Oyl. She's also done Little Adurey, Winky-Dink, and the Sea Hag. In fact, she started her cartoon career in 1931 as the voice and model for just about the cutest little cartoon heroine ever, Betty Boop the famous booo-a-doop coed with the saucer eyes, spitcurls, miniskirt so high her garters showed, high-pitched baby doll voice, Cupid's-bow mouth and perpetual pout. And at close to 66 (she won't give her exact age) Mae Questel is still cute. Oh, the hands shake a bit, perhaps, and she chainsmokes, and of course the miniskirt and red Cupid's-bow mouth are gone (the lipstick these days is orange), but she still mugs, paints her toenails, and wears a smudge of blue over her eyes; she still likes to get off a naughty remark while pretending innocence. She still pouts - if you take a look at her stills she seems to have gone through her career pouting - and she still often resorts to her trademark, cutie-pie voice.

How do you describe such a voice?

If Mae Questel were an instrument, she would be a kazoo. As it was, that voice made the career.

And recently, in her Upper East Side studio apartment, with second husband Jack Shelby nearby ("I don't want to talk about my first husband," Questel whispers, she talks about her career. It was, of course, a discussion over coffee and cookies were paramount. "Eat something a little more exciting," says Questel if you raeach for a mundane sugar. "You want milk? It's cream, actually. We got these from Greenberg's.You know Greenberg's? You got one downtown? This one is better."

Neither is Shelby, a retired newspaper librarian who wears a huge gold caricature ring of his face, a silent observer in this interview. He's written out a sheaf of notes for Questel when she seems to make any sort of disparaging remark, he prompts her constantly, and he tries to prevent her from discussing money. ("They all think we sit around and clip coupons, but I'm not a millionaire yet," says Questel of her finances lately, though adding that doing the voices for Betty Boop and Olive Oyl made her rich.) Occasionally Aunt Bluebell has enough of her husband's interruptions and turns on him with a "What are you doing?" Usually, however, she gives him a fond look, says, "He's the boss," and lets him talk. Star Image

About being Aunt Bluebell, she seems genuinely happy.

"To be a spokeswoman in a commercial, this is one of those things an actor looks forward to, you can sit back and do other things with a commercial," says Questel. "The kind of recognition I get from this commercial is like if I made 10 movies a year. It's very gratifying and I love it. People come up to me on the streets, in restaurants.

Last year we were at a Bar Mitzvah in Rochester and 100 people came in a snowstorm to see me. No. No criticism; once in a while somebody will say why don't you change your hat or get a new getup - I started with a very inexpensive dress, $70, and they copied it, to get it just the way it was, and it cost them now as much as $500 to copy that dress - but it's like a costume, they don't want to disturb the image, it's a small way of thinking.

"What do you mean it's a small way of thinking?" yells jack Shelby. "They spent all kinds of money, millions and millions to project an image, and you happen to be that image and it's not small at all, each word is weighed . . . "

"Ooo, you have no idea," says Questel. "Each word is sent over to the attorney to make sure there are no mistakes in the selling . . . "

"And it's Aunt Bluebell," says Shelby. "Aunt Bluebell who's selling.

"It's like being the lead in the show," says Questel.

"That star," says Shelby.

Does she actually use the product? Are those blue paper towels in their kitchen Scot Towels?

"Of course we use 'em," says Bluebell. "They give 'em to us, we use 'em, and give 'em to people as presents . . . "

And when we run out, we got to the store and buy them," says jack Shelby.

Whence the roots of Aunt Bluebell?

First making sure the coffee is strong enough, and that the newly-arrived photographer gets his cookies - and in between musical shouts to the photographer to "say when" - Questel tells her story. Family Pet

She was born in the South Bronx. Whitlock Avenue, the only daughter (there were also two brothers) of Polish and Russian immigrants. Her father had a successful embroidery business, her mother, though a talented singer and mimic, had not been allowed to go on the stage. She was clearly the pet of the family.

"My father always said to me, 'You're my lucky star,' because when I was 1 year old, the business became successful," says Questel, smiling at the memory. "I had piano lessons, dancing lessons, the whole bit. I was dressed to the teeth, with a leopard coat and red fox when I was 13 years old - can you believe it? - and boots to match and special dressmakers . . . and I was a mimic, like my mother; my brothers and me were all mimic."

The mimicry got her started in show business, when she won a Helen Kane lookalike, singalike contest at the Bronx's RKO Fordham Theater. (Kane was the original boop-a-doop singer; Questel imitated her so well that later Kane sued her.) Winning that contest led to a vaudeville contract, which in turn won Questel, in 1931, at the age of 19, a contract for doing the voice of Betty Boop. The cartoon, originally begun two years earlier as Betty Coed, was changed to resemble Questel physically. In fact, Betty Boop and Mae Questel became somewhat interchangeable for a while. Questel often performed her vaudeville song-and-dance comedy act as Mae "Betty Boop" Questel.

"I did a show where I could imitate wverybody that was prevalent at the time, even Eddie Cantor," says Questel. "I'd go to the Palace and they'd go on and I'd imitate them, that's how much guts I had. I'd also do a wood scene - that's where they break a piano apart and then a canor, and then an outhouse, and then I'd come out of the outhouse. This is after my own act . . . I'd imitate them all, I'd even imitate Jimmy Durante.

"You want to see?"

She leaps to her feet, a little 5-feet-10-inch woman, voice husky, doing a stiff-legged walk, arms flailing, "Woo woo woo, ring-a-ding-a-ding," she hollers, laughing. She sits back down. "I did Maurice Chevalie - can you imagine? - I imitated him in a Betty Boop cartoon, and I sat next to him at a Screening and while we were sitting there watching it - he makes a pass at me. I was so shocked, I was 19 and even if I had been married since I was 17.I was shocked, and then afterward he asked me to supper, and I said, 'I'd love to, just let me call my husband and tell him were to meet us.'" She laughs.

She glows for a while."There was something about me in those days, I never walked, I hopped. I was very much alive . . . There was this nostalgia thing, in Arizona, awhile ago, and I saw of the shorts I had made with Rudy Vallee back then, and I'd never seen them before, and well, I hate to say this, but I took a look at myself, and I wa so adorable . . . I couldn't look at myself enough . . . it's too bad I can't look at myself and say that now, not because I hate myself, but because in those days . . . how much of me was in Betty Boop? Oh, a lot, a lot. I'm still a real idiot, but I was especially then, bouncy, bubbly, never a straight face. I love Betty Boop, everybody loved Betty Boop. Olive Oyl, I wasn't so crazy about . . . "

Her husband interrupts again "Mae you're doing it again! You've got a big fat contract waiting for you to do Olive Oyl, so forget all this you're saying about Olive Oyl. Olive Oyl is on three times a day, that cartoon is on three times a day, so how bad can it be?"

Questel chooses this time to ignore him. "Some people really love Olive Oyl," she says. "I say, how the hell can they? So what if it's on three times a day, I don't have to love it. Betty Boop was a sexpot. Olive Oyl is a string bean, with an ugly puss, and a pair of legs that look like spaghetti."

"I used to do a lot of things I didn't like," says Questel. "Now, I don't like something, I turn it down. Like two months ago, I turned down a movie part with Goldie hawn an what's-his-name, Dustin Hoffman, something like that. Because there was a scene in that movie where I'm playing Scrabble and the camera pans down to a word, and when my agent told me what that word was, I shrieked . . . no, I can't tell you what the word was. I'm a square, I really am . . . 'No sir,' I said to my agent."

She discusses another role, nearly 20 years ago, that also made her uncomfortable, though she took it. "It was with Gertrude Berg, 'A Majority of One,' on Broadway," she says. "I had these lines where I say, 'I'm moving out of Brooklyn, after all, look what's coming in, Puerto Ricans, Irish, colored,' and the words just stuck in my craw . . . no, it made no difference, it was the character talking, not me, I hated to say it. Every matinee, every Saturday and Wednesday, the women in the audience would go 'ah' when I said those lines . . . and I didn't want it. I didn't want to be hated."

The afternoon grows dark. Questel discusses her family, says she grew close to Shelby eight years ago when he lost his wife and she lost her son, a psychologist, to cancer. She says her remaining son is a writer, and that no, unlike her other son, who fathered her 13-year-old granddaughter, this son doesn't have children.

She says that her husband, Jack, takes wonderful care of her. "An actress, no matter how old she is when it comes to disappointments and pressures is like a little girl." She says she wants everyone to know that even if she is in show business, most of her friends are not, and she is not one of those what do you call it, workaholics: she like to travel, Europe, Palm Beach, she likes to lead a normal life . . .

Jack Shelby interrupts again, "She's a great golfer," he says. "Tell how you got second place at Grossingers golfing that time . . . "

She looks over at him, not yelling this time.

"Him. He's my lucky star," says Aunt Bluebell.