How friendly is TOO friendly?

[Immortal Goat]

On my campus, as on most campuses, I would assume, people form their own little groups of friends and pretty much stick with that. Well, my campus is no different, and my group of friends is pretty large. One guy in particular, though, has been creeping me out a little lately. Here are the facts:

- Our group mostly sits around in the coffee shop on campus all day. When my girlfriend (now known as Lynn) is in there, though, and I am either in class or at my campus job, this guy (We'll refer to him as Jones) sits really close to her. As in REALLY close. She was on a couch all by herself, stretching and taking up two of the three cushions. He sat down on the third, and half an hour later, she's squished against the side with nothing but her backpack between her and him. The rest of the couch was still empty.

- Jones is a close talker with everyone, but he only sits close to Lynn on a regular basis, and mostly when I am not around.

- Today, Lynn sat down on my lap in one of the chairs. When Jones saw this, he left the coffee shop faster than you could say "jealousy".

- Jones writes fanfiction for the Lone Gunmen series (laugh all you want, seriously. I do sometimes). For a class project, he is filming one of his scripts. He asked if we could help, and we agreed. I got cast as some French guy, and Lynn as a woman who I am pretty sure gets romantically involved with his character in his later scripts.

- Last week was Homecoming week. One of the activities was a jousting competition (bigass inflatable room with foam weapons). I wanted to go against the winner of the previous match, but he insisted I go against him. I won, and he didn't come near me or Lynn for the rest of the day.

- Though he insists that he has a girlfriend, we have never met her, nor have we seen any pictures of them together. He never even talks to her, and claims that he only sees her on the weekends, but never gives specifics as to what they do.

So, basically, I am asking if you think there may be cause for concern here. If so, what the hell should I do?