What is going on in this guy's head?

Ok, please help me out with this, and it would be god to get guy’s perspectives on the situation too.. Ok so this guy who I’ve liked for a while now added me on msn randomly so we talked there and he asked me for my number, so naturally I was quite happy! So we texted for two weeks, he text me first, always. And then one night everyone was going out and he asked where Id be going, I told him, and he sidhe’d be going to a different club with his friends, which was fine. So went out with my friends and who was there at the bar only him, so we talked all night and I was with him and all was good, he text me for another 2 weeks after that, everything seemed fine. But in the last week he didnt text as much so I cut him some slack and text first for a change a few times and all was good, but now out of no where hes stopped texting me. Is it a mind game? Or has he suddenly lost interest for no apparent reason? Or is this a guy thing, a test? Im really confused, and I refuse to text him because if he really wanted to he would be texting me like he had been. Any advice? Or any idea what hes upto? Or maybe hes just lost interest! What do you think?