Probably you already have noticed some men who they are together with women in a club, bar etc.
This is not bad, but many people are afraid to approach a woman, while there is a man in her group.
Most of them are just “orbiters” and are men that are friends, colleagues or brothers with these girls. I recommend you the first thing to do is to watch if the girl touch or kiss any man of this group, before you approach this girl. You can understand very easy if there is any sexual connection between a man and a woman.
For example, a few days ago I approached a girl I liked, who was in a mixed set. I approached her only after I watched the people there and I saw that they are not having any sexual connection between them. The man was gay and a friend of my target. I couldn’t even imagined this, if I didn’t approach this girl. So, you never know how do they know each other.
So, don’t hesitate to approach a mixed group, but do it only if you are sure about their relationship.