1) How far do you trust your friends with your partner, and vice versa?
Could they spend the night together with an innocent excuse, and you wouldn't worry, for example?
2) If someone has been too trusting of the people concerned, eg, happy enough to let friends socialise with boyfriend whilst I'm off at work paying the rent, and I get cheated on, to what extent is that my own fault?
3) A boyfriend cheats with two of your close friends. Of course, he is a total loss to humanity and there's no point trying to maintain a friendship there. But do you mourn the friendship with the friends, even though they've done the nasty to you? How far would you go to keep that friendship alive?
Edit: Does it make a difference that he's now dating one of them?
(I know the third question sounds like a weak thing to ask, but in the position I am thinking of, imagine feeling as though you've already lost a lot of people who were important to you over this, and worrying about losing more to that cheating twit you once thought you loved)