I REALLY like this guy but..?

So i have a guy friend tha i REALLY like. He talks to me every class we even get in trouble for it . We usually mess with each other and he will say i hate u and i will say love you too! and he is always like woman! and we laugh. Well latly we have been getting really close and comftorable with each other. Atleast once a class now he will play with my hair or put his hand on my shoulder. But today we were in groups and he was putting his feet on mine even if i moved mine he would put his back on them. Also he kept touching my hand and tugging on my jacket. He is the sweetest guy and is perfect. He told me that he would always support me and when ever i would fall he would catch me even if it was off the highest mountain. Problem is is that he has a girlfriend... but do you think he likes me?? what should i do??