Well,it means exactly that he's a flirter and is not really an honest guy.
don't act like you like him !!
Your best friend is the one that you do EVERYTHING with. You can trust them and they can trust you.
Look at it the other way around. If he was with you but flirting with your friend. You should probably tell your friend.
ill kill him grrrrrrrrrrrrrrrr
best to do nothing. it will only hurt everyone involved
you"re means you are example:you"re my best sister. you"re my best friend
she is jealous of her or him
Drugs.
Stay their friend and support them through all they do and make sure you are always their when they need you
ask her who she likes more and if she likes your friend more pinch her and tell her off hahahahahah muahahaha
Wait
confidantA best friend