You don't. If you want to keep your friendship with your best friend then you should not date their ex. You will end up losing your best friend over a relationship that will most likely not even last long while you friendship can last a lifetime. SO don't screw up a friendship over a little relationship.
To make you jealous.
move on no girl would go out with her friends ex unless her friend said it was ok
because they were jealous of you and now they don't really like you
you should talk to the best friend or u shouldn't go out with him
You had a courtesy to ask your best friend if you could go out with her ex and since she has told you she doesn't mind then feel free to go out with him. 'Ex' means the person is single.
give him aids no dont give him aids u go out with one of his best friends
go for it if you both like each other don't let friend stop you if hes a friend he would let u go out with her !
Talk to your friend and tell her what you're feeling. If he or she accepts the fact that you do, go ahead and go for it.
Well it depends, if you are still friends with your ex, it would probably be ok. But enemies I would not. (Unless you really actually love him).
Make sure that she is okay with you liking her ex. Talk to her about it, but if she is not, respect her feelings. Don't hurt your friend, because if you are there for her she'll be there for you. Friends are forever, but boyfriends come and go.
You can still be friends with your friend, but just try to remember to not get to close to your ex, and remember that your ex may be trying to make you jealous (it is possible that they aren't though). It is OK to be friends with an ex.
i would think so. i mean im best friends with my ex