How can I fix the fact that I hooked up with my best friend's ex?

Dear loverheart, This is called a guilty conscious and this usually happens to people when they have done something just as you have. The great thing is that because it still haunts you means that you have probably learned from your mistake but maybe feel that your friend hasn’t really forgave you for it or you have not forgiven yourself yet totally yet. We all make mistakes and hopefully we learn from them…do you feel you’ll do it again? NO…you’ve learned your lesson. YES…then make sure that you have no contact with the ex at all avoiding him at all costs. In fact not seeing him at this time probably is a good idea anyways…Tell yourself you’ve learned, you are a good person who made a mistake and tell this to your best friend as well. Hug each other and promise never to do this again. In time you both will forget and start remembering how important your friendship is. If you find this isn’t happening seek out counselling and they can give you some great ideas how to help with the nasty guilty conscious. Sue…good luck