You have the icebreaker right there:

Hello there sibling in [of similar interest], how do you do?

I flirt:

I see that you are a person of [interest] culture, what is that you enjoy of [interest]?

Could coy:

Excuse me, but way I know what’s your fav. thing about [interest]?

etc.. But you already have the icebreaker, even if your words fail you.