Dear Carolyn: My boyfriend of five years, "Max," misses "novelty" in our relationship. We are in our mid-20s with career-oriented lives, and we make quality time together a priority. We have explored hobbies together, traveled and share many friends. He says I'm perfect for him and he could see married life together in the future but is not ready to settle down yet.

He seeks novelty by meeting other women for one-night stands under the pretense of ethical non-monogamy, since I know what's going on. However, I don't like it, and I have told him so. He states this is a need I currently cannot fulfill and he cannot be happy without. He would stop if I demanded it, rather than break up.

I don't like ultimatums. We're still together because he says this desire for novelty is "just a phase," and I could see myself with him long-term in a monogamous relationship. I also don't want to be closed-minded about relationships involving multiple partners.

Should I believe him and stick it out? Or am I enabling immature, self-centered behavior?

— Confused

Confused: I have no idea whether you should believe him. It does appear that doing so breaks in his favor vs. yours about 100 percent to 0, which would explain in one bite why he sees you as “perfect” for him (despite your no doubt being lovely for unique and substantial reasons), but maybe that’s just me.

Here’s the more urgent question: Should you believe yourself?

Your letter is uncanny at opening doors for Max to act in his own interests — he feels this, he envisions that, he’s not ready for whatever, he would do X upon request, he sees the future and exists in a realm above human nature!!! — while closing doors to your acting in your own interests. You “don’t like ultimatums”? You “don’t want to be closed-minded”?

You put up the walls, then run smack into them.

You can be open-minded in general about something and still not be a hypocrite for not taking part in it personally. You can support the local bar and not have a drink.

You, not a sociopolitical board of directors, set the terms of your own heart.

So. If you don’t like the terms of your relationship, then change them. If that’s not possible with Max, then break up.

That’s it. Maybe it seems drastic, but since you made no mention of his being perfect (or even okay) for you, or what you really, really want in life, it’s possible trying to make it work is actually too generous to him.

Even if I’ve misread you and you’re in deep, clear-eyed love with Max, then you still don’t actually have to commit to him now to hold the spot for him to commit to you later, when the novelty of novelty wears off and his hypothetical settling-down phase begins. You don’t have to keep him on layaway.

You can, instead, live your life without him, with the integrity of committing fully to your own principles, without the nagging sense that you’re making excuses for your own mistreatment.

Separating will hurt, but this relationship already hurts.

Should you both grow into versions of yourselves someday who really are perfect for each other, you can get in touch.

Write to Carolyn Hax at tellme@washpost.com. Get her column delivered to your inbox each morning at wapo.st/haxpost.