Whatever end to that line of thought Erik had been expecting, that definitely wasn't it. Even a little. It wasn't often that he was knocked completely speechless, but Charles had a habit of doing it.
There was more than a little inward flailing, but even that was short-lived, and he braced a hand against Charles' shoulder, just for a moment, he had, initially, intended to lever the other man off, but somewhere along the way that push turned into sliding that hand over against the nape of the other man's neck, just holding there. If asked, he wouldn't be able to say why aside from the fact that it felt like the right thing to do.