Compromise between mismatched libidos

My boyfriend and I are in our 20s and we have been together for six months now. 

We spend three or four nights a week together and we always have sex, but he isn’t satisfied by doing it just once. He wants us to stay in bed all evening — which would be fine occasionally — but I’d like to be doing other things with our evening too.

We’ll often have sex, start making a meal, and he will instigate it again, and again. It makes me feel inadequate, prudish even, that once a night is enough for me when he could go on forever?