I have never being so confused? Need some opinions?

well okay there is this guy i will make the long story short he is a mutual friend he always looks at me and makes gay remarks like "remember you kissed me when you where drunk in front of your GF" and "you owe me a kiss" and just flirty? hes like 3 years older than me im 17. bi (closet) and i said to him your gay and he said he knows he is and all that. but i just still think he is joking? But now he is dating my friend (girl) and me and him always used to make eye contact and now it hardly ever. he also asks about me like where am i if im not there and gets people to get me. so i really dont know he is so confusing? what should i do? is this his personality or is he just playing? OR is it just because he dosen't know what he wants himself? Help thanks :)