Sex doesn’t make him cum...

My bf wanks every single day (1-2 times). It’s gotten to the point where he can’t cum whilst having sex. At the end he has to wank to cum. This kinda makes me insecure because I feel like I’m just really rubbish. I’ve spoken about it once recently to him asking him why he can’t cum whilst having sex. He said he “wanks a lot so his dick has kind of gone numb...” when he’s “inside of me it feels good but it feels like it needs a really strong grip on it (like a hand)”

I don’t know what to do 😕

Forgot to mention we’ve been together for over 3 years. It wasn’t like this before. I’d say the whole not cuming having sex thing started about 2-3 months ago...