Don't write him off entirely OP, if you liked him and he liked you I can't see why you wouldn't give it another go. You didn't find him sleazy and only you know how much flirting/banter led up to his massage comments, so whatever anyone on here thinks, only you really know if he overstepped the mark.
he wants a physical relationship from the get go (show me a man that doesn't) exactly this (and the same goes for many women too!)
I met my DP online last year, we got on brilliantly, talked about all sorts, got very frisky in the bar and had such a fantastic date neither of us wanted it to end. He did come back to mine, we had a great night and have been together ever since.
I can imagine that if either of us had another date lined up for later that week we would have cancelled it, but if not, it was early days so I would have understood (but hoped that he didn't get on so well with her and came back for seconds with me!) As it happens I did have another date lined up for the week before, but I chose to cancel it and only see one man at a time, which DP found endearing as it is quite unusual in OD.
People seem to have the 'lets be exclusive' chat after several months these days, so him still being online today, going on other dates etc when you've only met once says nothing about him. It may be that he is replying to messages from other people he has been in contact with telling them that he has met someone lovely and can't meet up with them hopelessly deluded I know, but that's exactly what I was doing the week after I met DP!