When you gotta rub you gotta rub. Do you want to be with them? Yes or no? I dunno, seems like people getting their feelings hurt by their partner making themselves feel good while alone is dumb in the same way you have to navigate other trust issues in relationships: if they are who they are and you don’t want to be with them as they are, it’s not a good fit, and if you can, then great.

If they just want to masturbate and never have sex, and that doesn’t work for you, I guess you can try to change them, but in the end, you’re asking them to change for you.

Edit: oh, but be honest. Don’t lie about shit. If they asked you if you did and you did, just grin and say you did. It doesn’t have to be weird.