There is some precedent for the idea, though in a completely different context.
In Baldur's Gate II, if you romanced Aerie, to continue it you had to refuse sex the first time she offered it, otherwise she would call off the relationship later.
On top of not having to do the horizontal tango to continue a relationship, I would love to see something like Aerie's romance arc where, with one companion's romance arc, you need to refuse to sleep with them the first time to continue it, preferably making it clear that they're desperate for sex for the wrong reason(s), like with Aerie
