i have a boyfriend..but i really like his brother

im going out with a guy( on nikakoy sport nelubit...i voobshe kakoy-to leniviy)..i am way stronger than him, he smokes alot)..and then he invited me to come and meet his mum...and there was his brother..and his brother is everything what i like about guys(he is totally my type....he is into sport..and he is handsome(strong)and im falling for him...so please tell me what to do...i know he likes me 2...but i just want to know what to do...when my boyfriend is beying a total idiot..to my friends and all that
xxx atomic kitten masha