They can keep you posted on what they see and hear about this new relationship, as it's never fun to be the last to know.
Keeping your thoughts limited to this tightly knit circle will also prevent you from blabbering your opinion about the new couple to everyone.
When you and your friend are both in the "off-limits" camp, it's great -- it simply doesn't happen, because you both agree it's not a good move.However, when you're in different camps, and a friend dates your ex (or vice versa), this can lead to big trouble -- anything from awkward social interactions to permanent rifts within groups of friends.While we strongly suggest realizing there are many, many other fish in the sea, if you absolutely see nothing wrong with this and/or cannot bear to refrain from dating this person, here are a few tips to make sure you keep your friend: Talk to your friend: Ideally, you know that at best this situation is uncomfortable, and it's your job to talk to your friend.Your new partner (your friend's ex) should as well, but remember that they have broken up, while you and your friend are still "together." An explanation of how important your friendship is to you and a sincere acknowledgment of the awkwardness of the situation might help.
Until you're comfortable with the situation, it's best to avoid confrontation -- it can only make you upset and say or do something you may regret.If you're the person dating your friend's ex, you've got a much harder job.