What does this mean and what should I do?

[Ruby]

Basically I met this guy on twitter about 3 weeks ago, and we started talking. We like the same music and stuff so thats how we started talking, and then I added him on bbm and we've been talking non stop since. We get along really well, we make eachother laugh and he always makes me smile. But the thing is he has a girlfriend, which you wouldn't believe if you read our chats because he always seems to flirt with me and he says im his 'babygirl' and he always calls me baby, we send eachother photos too.. I've never sent him anything bad, but I guess you could say the photos are quite flirty, and he always calls me hot. And I know its bad because he has a girlfriend, but shouldn't he be the one to stop it? But he is kind of twitter famous and he always seems to be flirting with girls.. I don't know what to do because I feel bad for his girlfriend but I can't really say anything? Also can anyone tell how he feels about me because I'm not sure.. We did this thing and he said I was one of his best friends and also his babygirl, he also said he would kiss me? So I'm really confused, please can someone help? Just what I should do and what you think about it all?
Thanks!X

[Kettely J]

Dont do it he's a player. He'll mess with your head and sounds like a cheater to me and so if he leaves his girlfriend for you , dont you think he's going to do the same thing to you? And watch out for the type of photots you send to him could lead to major consequences ....