- Tell him
- He get’s pissed at you and claims jealousy calls you an Emo bastard etc.
- He moves away
- Later realizes his mistake once he contracts the HIV.
- Realizes that you really weren’t a douche, and that were telling the truth
- He realizes the error of his ways. Appolgizes, you get reach-around.
6a. Or he’s a pussy about it won’t man up and you never talk again.
Seriously though, tell him. Either way you go about it he’ll get pissed, don’t joke about it tell him once. He’ll most likely ask her at which point she’ll make up some story about you most likely in an effort to piss you off. At which point not getting pissed would help to get the point across.
If you don’t tell him, he’ll either find out later. Or find out after it is past the point of return. And if he finds out you knew he’ll direct his anger at you.
Make sure you are 100% certain, if you jump the gun it could be real messy.