Couples Sex Counselling and/or therapy.
Seriously.
If some other problem or imbalance was threatening your marriage (and no matter what you say about never playing away, this is threatening your marriage) you wouldn't think twice about seeking help to save it.
"It's about being unselfish and generous to the person you are supposed to love."
and this ^^ is how you explain to him that seeking such help together is non-negotiable.
Does he freely kiss you at other times, Dollymixture? Freely cuddle you, for example, to comfort you?
The fact that he wants foreplay (you giving oral) then wants you on top (sitting on his penis, I'm guessing, not lying with full body contact) suggests that there is a much bigger problem here (than "never really having great mind blowing sex").
It sounds like he is allowing things like genital contact (to get him ready for sex and then, obviously, in actually doing it), but he is not allowing intimacy.
It might seem strange to say that, given that you are having sex, but if you think about it the intimacy mostly comes from all the other things a couple do before, during and after penetration. Often simple things, like how he holds you, strokes you, interacts with you during penetration.