……do you think Fake Married for the +2 boost to AC is a trope in the D&D worlds?

Yes, I know you can only benefit from the Wedding part of Ceremony once unless your spouse dies, and the AC bonus only lasts 7 days, but sometimes you might really need that bonus right immediately now and be willing to accept that.

And then, of course, you’ve got to keep your divine caster’s deity from realizing it’s all a battle strategy sham for those seven days, not to mention not letting the BBEG realize you just got married for the AC boost because you’re about to kick in their door, all while remaining within 30ft of each other…