Is he a flirt, confused, etc, or am I just paranoid?

Hmm...maybe he just wants to be in love. The other girl (Jess), might have been a former interest, but he knows she's taken. It's possible that he likes you now, but the only way you'll know for sure is to ask him. Ask him about his feelings about Jess. If he really likes you, he'll appreciate the fact that you are interested enough to find out. Alot of this depends on how old you and him are as well. Guys in their late teens-early 20's are more likely to try to be "pimps", and seek out every girl that shows the slightest amount of interest. Then again, he could be different. You'll never really know what's up with him, unless you ask him. Good luck!