There is a massive difference between asking for an opinion on an outfit or asking someone totally out of context to rate your body and what has happened here.
He had JUST had sex with her.
In the first 8 weeks, he should find her sexy. Sexy is not that same as pretty or beautiful or unusually attractive. It is a subjective thing.
If he can't summon up the words to tell someone he has JUST had sex with she turns him on then he's an idiot.
I remember an ex of mine once telling me he found the shape of my shoulders really sexy. It was one of my favourite compliments ever (and stuck with me) - because it was so random that I figured it must be true. I'm no supermodel, so compliments about other parts were unlikely to have been easily believed by me, but that one felt genuine.
I was also told by another (when I was unhappily overweight) that they loved one particular curve on me - and ran his hand over it to illustrate. He said it was the same curve regardless of my size.
It's not difficult to tell someone you are in a new relationship with that you fancy them - and it's not an interrogation.
No lies are required. 'What do you think of my body?' can have a million and one true, complimentary replies no matter what the body is like.
'Er...fine' isn't one of them!
It would be different if he made you feel like you didn't need compliments because he treated and behaved in a way that meant you didn't feel the need for them, but that clearly isn't the case here.
This one's not for you, OP. Back in the sea for him. There is a better fish out there.