Whats wrong here?

[Ina]

So i meet this guy that knows my ex and we see each other like once o week so since 4 months now and he knows i like him and i know he likes me too because i can see from how he acts and talks to me but...i dont get him at all..i wrote him an email saying that if he doesnt want more from me then he should stop calling me and then i thought that i was a mistake what i did and i wrote him again saying that he should ignore my fist mail ,so he did and we started talking again.Now what happend recently was that he was out of town and out of no where he sms saying that he arrived saftley and that he cares for me ..He came back on Monday called me up after work asking what i was up too and maybe we will here each other on the phone later if he is not tired ..and after an our he called saying that he is going to meet up with a friend from work and if i want to join he would be very happy ..so i did and there where more people there even a nother girl that likes him but all night he was talking to me and interecating with me making jokes with me and you could see he was into me so to say ..and then ..nothing!Since Monday he hasnt called or anything and he does this everytime .We meet up and then never calls back after a week or two ..can someone please explain this behavior to me because i am going crayz.I have really no experience in dating because i only had 2 relationships all my life for 4-6 years so..thank you for those that answer.