Set aside time for each of them and honor it — don't drag your lover along on girls' night out (not even if your lover is a lady; queer chicks are 4. Don't ask your man if you're prettier/smarter/better at Scrabble than his last girlfriend.
Don't do this ever, but especially not if his last girlfriend is the person you're going rock climbing with Sunday.
The reverse is also true; no matter how much you love discussing your dude with your besties, his ex can probably live without hearing the details of his current sex life. It's OK to come to your partner for advice if you're arguing with your friend, or vice versa, but absolutely resist the urge to belittle or insult one of them to the other.
Trust that your friend is happy you've found someone you dig, not plotting to sabotage your love.
Lots of people have told me unequivocally that they would never date a friend's ex.
They wholeheartedly believe that it's wrong, disrespectful, and if a friend did that to them, they'd never talk to that person again.
And don't ever use jealousy or insecurity over their past relationship to excuse irrational or controlling behavior on your part.
Of course, if your sweetie gives you a legitimate reason to believe he's untrustworthy, get out of there stat, but if there's really nothing wrong, don't create problems where none exist.6. It may be tempting ask your friend to analyze what happened between the two of them so that you can avoid making the same mistakes, but resist that urge.
Remember that you can love them both without them necessarily having to enjoy each other.