Well, if someone other than other than rt or robieieieio is allowed to post a comment, I can tell you about a line that should work, but didn't in the case of one particularly ardent admirer:
I was on the subway in Toronto, and an older black male named Abraham comes up to me and starts hitting on me. I'm not interested in going anywhere with you, I tell him.
After a little more of this, I finally tell him the truth. "I'm a lesbian."
"What's that?" he asked.
(Me, thinking, OMG, this guy is soooo out to lunch.) "I prefer women to men."
He didn't get it. I finally told him I was going to a church conference of mostly gay men and lesbians. He wanted to go with me. I almost let him. One of the pastors who was leading the conference is a big guy, and would have made short shrift of him. But he stopped following me once I got on the streetcar.
But I really don't thing the lesbian line would work for rt or robieaieieio. Though you never know. Why don't you give it a try and report back?