Cannot stand power imbalances. Relationships founded on things like boss/assistant, teacher/student, and huge age gaps can be and usually are dangerous and/or super toxic. I do think it could be done well if it's portrayed for what it is- toxic- but I think it's super irresponsible of the author to romanticize that kinda stuff.
I think this kind of falls under the same umbrella but I also hate romance stories involving some sort of contract, business deal, or trapping someone in the relationship for the same reason. It's just plain scary to me, I don't care how 'sexy' the dude who forced you into a contract marriage is, it's still abusive and terrifying. It's no better than a romance between a kidnapper and their victim.