Not a bloke, but i've been in similar situations, so this is miy thoughts.. Men do the drunken call thing, only women do it when drunk and emotional, and men do it when drunk and horny.
My guess is, he was feeling drunk and horny, thought about you, knowing you have had a few fun times togther since splitting up, and texted hoping for some nookie...
Then, after some texting and chatting, he started to sober up, and realised his horn was dying and coming over would be hassle, when he now just wanted some shut eye.
He also didnt want the hassle of having to deal with you in the morning, especially if he is seeing someone- he tells you its noone special, but guys dont always tell you everything!
Dont take it personally, and dont waste time thinking about it, or him. And if i were you, dont invite him over for any more nookie sessions. It may seem harmless and string free, but it will stop you moving on properly.