It’s not about having no out, it’s simply the observation that it doesn’t make much sense in that regard.
Finally, someone said it.
It's not about being able to avoid the situation entirely, it's that the situation itself is nonsense - like you said, Ann and MC have never discussed sharing before, but suddenly, she initiates a threesome with those two guys and MC nods in affirmation? Since when?
I don't want to hear "hur-dur don't play the scene then" I am bringing to your attention that the situation itself is out-of-place and needed more setup.