A Guy Who Is Trying to Date Me Talks to Other Girls Online Behind My Back. What Do I Do? Can I Trust Him?

[Jae]

2 weeks ago I got a random facebook message from a guy I met in college. (We shared a class last semester and he showed alot of interest in me: stealing glances, staring, telling other people that I "seemed interesting and he wanted to get to know me but I'm so quiet.”) Anyway, we exchanged numbers over fb and have been texting on and off for going on 3 weeks now.

I randomly saw him over the summer at an event and he complimented my jacket, and asked what brand it was. YESTERDAY I saw him at another event (I told him I'd be there on business and he said he was going too, but he literally only stayed like 10 minutes because it was a boring place) Anyway, he said:

Him: I like your necklace, Mickey mouse?
Me: Thanks, it's from kingdom hearts.
Him: *awkward pause* actually I like your whole outfit today.
Me: *awkward and shy, looking down at the ground* thanks

We texted again today, and he asked if he'd get to see me soon. I asked him when he goes back to school (he's on winter break from college right now) and told him I would try to see him before then, but he never responded back. Stalked his twitter today, and saw that he was making plans to chat with a girl at 10:00pm. I also found it he talks to girls on Omegle sometimes. I don't know what to do about this. Can I trust him? Do I ignore these interactions with others girls?