Orlantis
Not to be rude, but he is a guy. You could walk up in the nude and literally say, "You know what I want.", and if his response isn't your preference than there is an underlying problem. While I am sure he worries, somewhat, about stamina after a recent ejaculation if anything it prolongs the actual act of sex when sex comes in tandem to masturbation.
As for pain I believe it is more apt you are both tightening muscles. The best way to deal with this is a warming gel like tiger balm or something to relax the general area. Just attempt to keep it out of your v****a.
Also, and this may sound rude, but he could be seeing someone else without your knowledge. I really hope that isn't it, but it is quite possible considering the sex drive of men. If that is the case than you're better off moving on as quickly as possible so as to deal with the pain to come and get through it so you can be happy with someone else.
NO, this isnt rude, it is sexist and wrong. Having a p***s doesnt make you any more or less into sex than not having it. Humans are way too complex to narrowly define their behaviours and wants in this way.
Not all guys are really into sex, and guys do have other thoughts beside it. Just like there are girls who are really really into sex and think about it more often than some guys do.