Why not, if you remain friends.
Only with the friends explicit approval Yes it is.
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.
It is never okay to date your friend's ex-boyfriend.
move on no girl would go out with her friends ex unless her friend said it was ok
if its ok with her but you gotta remember your not a couple any more
The one mistake you made dating your best friends ex is not discussing it with them first to see if they would be OK with the idea. Best friends should last forever and should never let a guy/girl come between them. It's time for you to communicate in private to your best friend that you made a mistake by dating their ex and wanted to let them know and if it was OK by them. If not then stop dating the ex.
Yes if you dont want to be friends anymore then do it unless he is ok with it then u can still be friends and then every thing is going to be just fine
Ask your friend if it's OK to make a move.
I'm going through the same ting my friends ex asked me out but if you like him/her say yes but if u don't say no but first ask your friend if its ok.
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).
Generally no, it is not a good idea for your sister to be friends with your ex and it can lead to some uncomfortable moments in the family. If she sees him at other places and does not involve you or the rest of your family then she is free to do as she wishes.