Should i tell this guy i like him if my best friend used to?

ok so i like this guy but i dont know the right way to tell him
or if i should tell him because my best friend used to like him can someone please help me!!

How long ago did she like him? And why does she not like him now? I would talk to your best friend first and find out. I would tell her that you like him and ask her how she feels about it. Usually the rule most girls follow is that if the guys is an ex of one of your close friends where they actually dated, he's off limits. THerefore, if they didnt date, and she liked him quite awhile ago, I think you should go for it. You're not stealing him away or anything, especially if your best bud has a new crush. If she stopped liking him because of something bad he did, I would think about that and whether or not you should pursue him. Good luck!