What should i do? Hang On, Or Let Go for a While?

okay i seriously believe i could be in love with this boy, his name is Alec, And i really wanna be with him, like, A lot!!!! He tells me he loves me all the time,and a lot of other things , he always makes me smile, and honestly i could see us spending our life together, but there is one problem, he has a girlfriend,he wont break up with her til they fight again,god only knows when that'll be. =[ and i feel horrible, but she lives in indiana, while he and i live in grove city, tho he tells me he's in love with me? please help,i dont know if i should just let him go until its over with them,or keep hanging on so i dont lose him.