I like two guys..help?

okay wel i hav a boyfriend he is the sweetest thing ever its like he would do anything for me. however my ex is bk on the scene and he treated me terrible the first and second time we went out (dumping me by text before valentine..saying he wants to kiss other girls and go out with mates instead of me) however his personality is just so attractive it hurts. my boyfriend is shy and i just feel like i hav a better time with my ex.. i know tht sounds terrible coz i love my boyfriend! also i can imagine my future with my ex and not my boyfriend..i dont mean to it just happens..its so annoying i just wanna be able to love my boyfriend as he is perfect and wht i always wanted.. what can i do ?