My wing has been using this line when talking to girls.
He is not part of the community and does very direct approaches which work very, very well for him. One of the things he asks them is "Are you attached?"
It works for him.
Girls become indignant if they aren't ...."What!? No!" which leaves a nice opening for him.
And if they have a boyfriend but aren't happy in the relationship, they will usually answer "No" instead of getting into a discussion about the boyfriend