For what it's worth, I was never under any delusion that these youngins were looking for love from someone old enough to be their mother. I am fully aware of what they were looking for.
Ivy, I think if it's an aquantance it's pretty much fair game. But if it's someone who is in your close circle of friends it is always best to ask. Although I have a firm rule against it even if the other girl is ok with it. It has the opportunity to become drama, I try to avoid drama whenever possible. It comes up easily enough on it's own, I don't like to invite it in. Not that I haven't on occasion broken my own rules due to drunken stupidness, but I really do try to stick to the rules I have set for myself.