How Is It Relevant?

Had dinner with AH & MH last night.

In one of our conversations, we discussed possible travel plans to New York or San Francisco. I told MH I really preferred San Francisco. New York always seemed hostile to me as a city.

MH then told me we could do a San Francisco-Los Angelos-San Diego route.

Me: What's in San Diego you want to see?
MH: I have a friend there.
Me: A real friend, or someone you met online who might turn out to be a serial killer?
MH: A real person. My sister has met her.
Me: And you want to meet up with her?
MH: She's bisexual.
Me: (befuddled) How is that relevant? Unless you want to screw her.
MH: Too bad she's with her boyfriend.
Me: Then how is it relevant?
MH: It's relevant to you too lah.
Me: ?

How the hell is the sexuality of your friend relevant unless you want to fuck them?