Some good points there Magdlyn
I don't insist on watching her no, she has had both long term female and male "fun-friends" that she often had fun on her own with or would go to meet them so that's not a problem as long as I know she's safe.
Feelings will happen and we know this and it is part of what we want but,
Being on the scene we have been on going on 9 year, we have learned to create rules, one being that "if feelings get to stong on either side of a relationship that Shaz has with someone then that relationship has to be broken before it gets out of control" as at the end of the day our marriage has to be the no 1 priority
I think as long as it's made clear right from the start that it's just a casual and won't ever be no more than a part time bf / gf then shouldn't be a problem.
This is all why we are wondering if a polyamory site is for us as she don't want another full time partner so asking for advise from people in the know like yourself