Is it ok to start dating a friend of your ex boyfriends?

My boyfriend broke up with me a few months ago….a friend of his became a friend of mine and when my boyfriend use to avoid me when i was upset his friend would talk to me over msn, once, I asked him if it was ok to call me because i needed to speak to some one, he called me straight away and comforted me while my boyfriend avoided all my calls. He’s so nice and asked me to have coffee and compliments me most of the time, he says we should defiantly catch up…does this mean he likes me? a week after my boyfriend and I broke up he still avoided me and I said if you really don’t want this anymore tell me you don’t love me “because when we broke up he said he still loved me” and then he said he doesn’t love me and doesn’t care enough. two weeks after we broke up I asked him if he had been with anyone else, he didn’t reply and I was getting worked up so I told him off saying he should get a job and that stop chasing after popularity and your looks are the least important thing and if he wants to improve something he should focus on university. He sent me a message back saying I should let this go and move on and that he has already moved on.
what should I do?