hellppppp

I've been seeing (dating?) this guy for 6 months and the first night we met we hooked up. I didn't think things would turn out the way they are now but we hang out at least twice a week and I always sleep over when we do hang out and we usually spend the next day together (I'll sleep over and leave around 9pm the next day). I've left a few of my clothes there also and he really treats me like a girlfriend. I've met all of him friends and he invites me out with them every weekend and I met his cousin when we spent New Years together. He told his mom and co workers about me and all his friend keep telling me that I'm different from the other girls he's dated and that he really likes me but I've never heard him say it for himself. I don't even know what to say when people ask if we are dating. And I'm wayyy too shy to ask him myself, I always think about it but never do but I just want to know if I could talk about him by saying he's my boyfriend!!??  Also I'm 18 and he's 26.