So . . . these things aren't to blame, but you don't think people should take part in them anyway? And make rules about them??
I have one of my ex-boyfriends as a friend on facebook. He started out as a friend before we dated, and we're friendly now. We're both married and have a child with another person, but we chat every now and then. My husband has his ex as a friend on there too. By absolutely no means are either of us "tempted" by these people. Breakups happen for a reason, but that doesn't mean I want my ex completely severed from my life.
Nor am I "tempted" by any of the people I see at my local bar when I'm out solo (or I wasn't before the baby when I had opportunity to go). I think having "rules" against this would be utterly suffocating, and THAT'S the kind of thing that causes unhappiness, which can attribute to cheating.
I completely trust my husband to leave the house without me, socialize with or without alcohol and with or without other women. And he trusts me to do the same. When we come home, we talk about our feelings so we never have fights that cause those rough patches. Maybe I'm just lucky.