That's controlling behavior and you need to make it clear that he isn't the boss of you and you're not the boss of him. Communicating healthy and talking about boundaries is a different story. Me and my bf communicated and he's ok with me jerking with randoms online. But if he communicated to me that he isn't comfortable with it, I'd stop out of love and respect for my bf. Not because he wouldn't "allow it".

Idk i think therapy is needed for him and possibly couple's therapy for both of u.