Be the good friend you are and tell her your honest feelings about this guy, but don't be surprised that she defends him and won't listen to you. Most people in love refuse to believe the worst about the one they love so she is going to have to learn the hard way. Just be there as a friend to pick her up when she has the 'great fall.'
Catch him on film. Use you camcorder make a movie of him and the reaction of those that are around when he's acting a jerk. let him see it. If you are embarassed to be with him just tell him when he grows up give you a call.
You cannot convince another person to give up their lovers, unfortunately. The best you can do is to be sure she notices him being a jerk. Anything that you do or say to try to turn her against him is going to backfire and make her mad at you.
Try to convince yourself he's not worth it. Find someone new.
Maybe. My daughter married her ex's best friend. They both discovered her ex was a jerk.
Leave any of this to your wife and her friend - its best that you do not get involved.
It didn't take much to convince the jury.How can I convince you to come on a date?
Your best friend might be dating a jerk because they dont like you anymore, try asking your friend to spend more time with you
You can't convince him. You can tell him and your reasons for thinking he is not a good friend but ultimatly he must make up his mind.
Avoid him like the plague. He is not good for you or your friend. I would let her know in a gentle way that she is dating a jerk. Best friends are forever. Boys come and go.
What should you do if your friend thinks he's better than you
Suggestion: Convince them to do something more fun to them then runescape.
You mostly like a jerk because you don't mind. You are with that jerk because he or she gives you what you want. Such as sex, money, or just someone who will date or marry you.