My friends and I always warn each other when a hot girl is approaching by saying boner check to each other.
Of course we wanted to warn each other without sounding like douche bags or pervs, so we started saying B.C.
Bravo-Charlie just sounds better than just saying B.C.
ex.2) "You got a Bravo-Charlie approaching your Six."
"Bravo Charlie" or "Beaver Curtains" (noun pl)
: The vaginal labia majora of female mammals, namely the female homo sapien.
• Hey, Brianna, come near me with that pair of man-scaping scissors and I'm going to kick you in the Bravo Charlie.
• That girl had a Bravo Charlie that I wouldn't touch with your transexual mother's meat sleeve.