I work in a large shopping center and I am flirtatious with most of the female customers and especially the female staff regulars. I use the same fun and friendly attitude towards the male customers and apparently a somewhat flamboyant gay male added me on facebook, told a mutual friend that he liked me and wanted to go out partying.

Since I'm not interested in sexual relations with males I wonder how I should nicely but firmly make it clear that I only play for one team, without hurting his feelings. Added to that question, does his attention mean that I send out a insecure vibe about my own sexuality since he probably wonders if I'm gay as well, although I'm fully clear that I'm heterosexual.