How do I know if my co-worker likes me or just being friendly?

[sylviakiss]

He always gives big smiles when we meet in the morning, and then he smiles at me a lot during the day. He sometimes touches my back or shoulder (playfully), and once (while showing him a document) he has invaded my personal space by standing so close to me that our arms and legs on one side touched all along froms shoulders to feet. For at least one minute we both leaned against each other, beside another and neither of us stepped back. I have to admit that I am very bad at reading signs and sometimes he sends me negative signals as well, like ignoring me, looking away when he catches my eyes etc. It is also possible that maybe he is just friendly (only because we are colleagues), and smiles at me only for the purpose to socialise with a coworker. Maybe he is just a bit touchy feely without any other intentions. He hasn't asked for my phone number, asked me out etc. Also, I had a boyfriend when I started to work here. I'm not sure if he knows about him, but it was not a secret, most of my colleagues were aware of it. So he might have heard about it. Not sure what he thinks now after that one minute when we leaned against each other