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]

3 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 ever since.

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. My sister literally asked me if he had just come to see me, and looking back, that seems to be the case.)

Anyway, he complimented me again yesterday said: 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
Before he left he said if I was ever in town again I should let him know.

When we texted yesterday he asked if he'd get to see me soon. I asked him when does 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 later that day and saw that he was making plans to chat with a girl after work 10:00pm. He texted me early this morning apologizing about how he was SO tired after work, and went to bed right away, and asked how I was. I haven't responded to his text. I don't know what to do about this. I don't really trust him. How can I? This may seem like a small thing to some people but he still lied to me. -_- Do I ignore these interactions with others girls or what?