[ He doesn't want her to realize. He wants to keep this as something good, even if that means perhaps pushing further than he should. It's a good thing that she's kept in the dark because maybe then he can find his way back into something light and if they think about it, if they talk about it he'll start questioning everything and down that road lies ruin.
No, all the better to just push into it and not think. Thinking can wait for later. He slides his hands carefully up her thighs, avoiding the bruising best he can to wrap around her back and kiss back with an intensity that could very well wash away the last few weeks pain and awkwardness. ]