i was really confused by the whole story... Ok first of all this SLP is exactly what u say
anyway, lets talk about the boy now. from what u say i think he likes u, he seems to be interested in u, and i m sure that u would be ok if this SLP was not in the middle... i dont understand how can a boy consider her to be cute... but, since he hes shown an interest for her, u should just give him time to decide. let him choose what he wants and dont press him.
he knows how u feel so, its his turn to decide and make a move now. u should let it on him. try to behave normal, be friendly and act like nothing is going on and let him decide. i think he likes u and will choose u since u told him u like him too. i dont think there sth else u can do, cause if u do sth to her, u ll be the mean one.. tell us what happened!
good luck