Talking to this guy online?

I'm 17, and I met this guy on Twitter that's 18. We've been talking for a few weeks, and used the webcam for the first time today. We talk on BlackBerry Messenger all day. He sends me a "Good morning :)" or a "Hey :)" everyday without fail around 8 or 9am and continues to talk until around 10pm at night. If I don't answer something he says, usually within 20 minutes he says something else, and tries to keep the conversation going. He's asked a few times if I had a boyfriend, or if I wanted one, and why I didn't have one. He asks what I'm doing a lot throughout the day, and shares details about his life/day. He sends pictures of stuff he's doing. He's told me I was beautiful, and pretty, and how funny and nice he thinks I am. He's asked me if I like someone a couple of times, and today asked, "So who do you like now?" And then added, "Someone that's not a close friend." Because he knew I had liked one of my guy friends before. Earlier when we were on the webcam, I had my blanket around me, and then a couple of hours later, he mentioned on BBM, "Haha, I love how you had a cover around you :)" And my sister said that since it had been a couple of hours, that he must have been thinking about it. He's told me before that he can't believe I'm single, and that he thinks I'm too pretty for most guys. He's also said, "You are so funny, it's amazing! :D" We talked on BBM literally all day, everyday. I've asked him who he liked whenever he asks me, and he usually says, "Uh, no one really..." My friends think he does, and I want to know, because I don't really like him that way.