Poorly Phrased

Conversation the other night:

A: Hey, incest is illegal, right? What about a threesome with two sisters? Is that illegal?
B: Asking this for a reason, or...?
A: Just curious as to what the legal definitions are.
B: Hmm... no idea. I-
(Pause)
A: What?
B: I was going to check the internet, but realised searching for “same-sex incest threesome” is unlikely to produce the results I want.
A: You could... no, wait. Adding ‘legal’ to the search probably won’t improve things.