How do I convince him to let me masturbate?

Hi, Me and my BF have been in this relationship since last 3 years now. Sex is great - 6-7 times a week. Recently, he wouldn't let me wank front of him. He says if I wanna get it on, we'd have to have sex. There's virtually almost no mutual fapping which I like the most. Because of this I've almost lost my fapping appetite (I don't feel like playing with myself even when I'm home alone). Thus, whenever we have sex and he makes me cum, it just hurts down south. How do I convince him to fap mutually or let me do it by myself? How do I ask him to join me (or give me a BJ) when I'm pleasuring myself? Please help.