need advice

So I'm gonna try to make this short as possible, I'm 16 and I like this long distance guy who lives about a hour away. he is 18. we have been texting for about 4 months. He says wants a relationship with me and says I'm cute. I have treated him so good and been so loyal. I tell him the guys I text but he doesn't for me. he said this last Monday that he wanted to be my MCM. And I put it as him. but today he puts another girl as his WCW. So we got into a big argument about it. he makes up excuses saying he is single, which he is but he cant be all flirty towards me and saying he wants a relationship but be talking and flirting with other girls?... That's so wrong on many levels that he don't understand. he says I care too much and that I'm ridiculous. I'm at lost and don't know what to do. Please anyone give me someone advice.