It is difficult. He feels rejected and hurt. She feels put upon and pressured.
No doubt his acting in this way even though he knows she dislikes it is part of expressing his aggression towards her for what feels like her rejection of his love. Women make the mistake of thinking that sex is just about the slaking of a mere appetite for men. It isn't, and a man who is constantly rejected sexually usually feels very hurt.
That being said, it doesn't excuse it. He ought to have the maturity to sit down and talk about how it makes him feel, then he woudln't have to act out in this juvenile way. I bet that if he was able to sit down and tell the OP that he loved her and he felt very emotionally hurt by her lack of interest in sex with him, he would feel much better. No doubt the OP would desire him more too and understand much better.
As women, can I ask, how do you know if you want sex or not? How do you know whether to say you aren't interested when your DH comes on to you? For me, about 20% of the time I am totally not interested. Another 10% of the time, I feel very interested, enough to initiate it myself or send out very clear come on signals.
But the rest of the time, ie the majority, it falls in between the two. So when DH makes a move, I am not actively interested, but usually I get interested after a few of DHs moves and generally warming up a bit. But had DH asked me right at the beginning, I would have said I was not interested.
I do think that you sometimes have to go with the flow a bit and you will find actually it was very welcome and you are glad your DH made the moves and made it happen!
Of course you have to feel confident that your DH will respect you if it turns out that you want to say "No" after all.
Does this ring a bell with people?