I’m horny and I want to have sex.  I’m aware that I could easily have sex with other people but honestly, the only person I want to have sex with is my ex-boyfriend.  Do you think it would be unhealthy if we had sex again? We ended on good terms but I really miss him. It’s kinda like, my heart says no but my crotch says yes, kind of thing.  What do you think?

Do what you gotta do. Fair warning, though. Whenever your heart says no but your crotch says yes, acknowledge the likelihood that you’re fucking up, and be willing to accept any negative consequences of your actions.