He's letting his eyes close when she slides her leg between his because that's niiice and promises all sorts of good things and then she says something and he isn't really listening but then suddenly he is because ow.

It's a fairly instant fold and crumple because yeah, he wasn't expecting that, had no defence against it. Lucky he was already leaning on the wall really, so he doesn't fall over - Mary Anne will probably have a nice bruise on her shoulder where he bent forward and accidentally headbutted her though.

'...!'

No sound except a small grunt of surprise, and then he's all silent, strained, agony. But that flush starting at his neck and creeping up over his face? That's fury as much as pain and when he can breathe, he's going to have a few things to say.