The New York-Washington commuter marriage is complicated enough. But Katmandu-Dacca?

"Oh, goodness," said Jane Coon, the new United States ambassador to Bangladesh, "if I'd been in Latin American and he'd been in the Far East . . ."

"He" is her husband, Carleton Coon, and new U.S. ambassador to Nepal and guest of honor at a dinner party at the Moroccan Embassy last night. He knows Moroccan Ambassador Ali Bengelloun from way back, and besides, Bengelloun likes to give parties.

"I think the marriage will survive," Carleton Coon said over cocktails. "We wouldn't have taken the jobs if we hadn't been fairly confident on that score."

"We're going to miss each other, obviously," said Jane Coon.

Katmandu, Nepal, and Dacca, Bangladesh, are about 500 miles apart, as far as the Coons could judge by measuring with a ruler on a map. They plan to see each other about once a month, via Biman Airlines of Bangladesh.

Charleton Coon leaves Saturday, so the party for 40 was neatly squeezed in. A sampling of guests: Nepalese Ambassador Bhech Thapa, hotel owner Marshall Coyne, journalist Carl Rowan, newly confirmed Peace Corps director Loret Miller Ruppe, wife of former Michigan congressman Philip Ruppe.

It was another of Bengeloun's carefully orchestrated evenings, beginning with drinks served by swift waiters, then moving to low-to-the-ground tables where everybody spooned from the big dishes of couscous or lamb in the middle. Bengelloun, the closest thing to an ambitious Washington host since the caviar days of former Iranian ambassador Ardeshir Zahedi, gives these parties regularly.

And like everyone else on the social-political circuit, Bengelloun gets plenty of business done during these evenings. Sometimes he's subtle. Sometimes he's not.

Last night, for instance, he gave a toast, first thanking everyone for coming and complimenting Carleton Coon. But then he directed his words right at Rep. Howard Wolpe (D-Mich.), the chairman of the Foreign Relations Committee's African subcommittee.

"We are very concerned in our area about the liberation," he said to Wolpe as the guests listened. "It is very long to explain that in this social evening, but I'm sure we'll have many meetings." Bengelloun was referring to the was Morocco is fighting with Alegerian-backed Polisario Front guerrillas over control of the Western Sahara.

"I was glad to hear the comment," Wolpe said afterward. His committee is pushing for a negotiated settlement.

As for the rest of the party: The weather being what it is, and party conversations being what they are, it was bound to come up.

"I like this weather," said Rep. Sonny Montgomery (D-Miss.), who came with a young woman from the White House staff. "It's hot enough to make the rattlesnakes and cotton grow."