More than one club we've been to has had a "triad" or bring a friend special price. If the friend was a single guy, the rule was he was to stay with you and not wander off by himself. In fact he was our responsibility and our reputation in the club was on the line based upon his behavior. Fortunately, the two or three times we've done it, the guy we brought was someone with whom we were good friends. Bonus for him, although he was with us, he got to make connections for future fun.
As long as the party or club makes it clear that's part of the evening, everyone can see it and choose to go or not. Fun is fun.

