Ok, so hear me out. "Gaydar", but for Bisexuality.

BI-FI.

"Are you getting any Bi-Fi in here" "I only have like two bars of Bi-Fi" "Why is there no Bi-Fi in here" "The Bi-Fi signal is great in here"

And my favorite: "What's the Bi-Fi password?"

And for Pansexuals... PAN-SCAN