Hentai, I can't remember the name.
These thugs hold a girl hostage, and make the guy pictured do stuff so she won't get hurt. He has to suck them off, crossdress, wear a diaper, get molested on trains, have fake periods(?)
Then they do SRS on him and attach his dick to his gf's body so she can fuck him with it.
Good luck finding it. Maybe ask /d/?