I like him and he likes her?HELP?

i liked this guy because i used to think that he likes me too because he showed me some very strong signals like he used to say awww you are a nice person or you look nice....used to walk me up to my lessons even though if he had to go to another building.....or whether he had to go to librery(he hates librery but if i ask him to go he will go with me) but today my friend told me that he was asking for this girl number because he apparently liked her. What shall i do?Shall i start to ignore him or just act like i used to act before pleasee help