I've tried that, more sex please! He has some reason why he can't: more later, in the morning, that's enough for now, tired, etc.
That's has been the light hearted approach up to now.
I have also been subtly asking for a wee while now. He has said I that expect more than other partners. Question is do how far do I push the questions? or just deal with it? If he can't then he can't and work on being more accepting?
Me: 40s female
Prof: 50s male.
Kip: 50s male.