Have you ever delayed introducing your new man to someone because you were worried he might find that person more attractive than you? It might sound strange, but I don't think it's quite so far-fetched.
I've had a close friend tell me that she has purposefully put off introducing a new man to her attractive friends. I don't think she was afraid we would try to steal him from her—we have very dissimilar tastes in guys—but that didn't seem to matter. And since I was included in the group she considered "attractive friends" (just stating the facts), I can attest that, despite telling her on numerous occasions that she didn't have anything to worry about, it didn't seem to diminish her fears.