I'm going to edge towards the no strings option. Mainly going by the fact that he's suddenly stopped texting and chatting. Most guys understand that if they sleep with a girl then she often starts worrying over whether it was just a one night stand. Usually if they are interested in more they will be in touch to stop you feeling paranoid. If he seemed like a pretty straightforward, honest guy and was interested then he would have got in touch to say that was nice, looking forward to seeing you when you get back.
Of course he hasn't done anything wrong per say..but by not really clarifying what it was before things happened the opportunity was there for him to get sex and bugger off guilt free. If it has been 4 or 5 days now and still no word then I'd say cut your losses and leave it for now. Let him get in contact if he wants to speak to you. See how things are when you get back and enjoy your Christmas without getting too concerned over this guy. Going back to your original message he probably doesn't consider sleeping with you to be a mistake..it's just that maybe his expectations for what happens after were different from yours.
Kate xx