When you are thrusting into that female private area at a high pace
Person 1: mate, I was proper vigorous with that lass last night
Person 2: oh sick charva! Good on ya
When you wanna call someone bby girl but they're a guy and you guys are no-homo so you call eachother bro-by girl
Person1: you're my bby girl, no homo tho
Person 2: so I'm your bro-by girl?
Person 1: yeah bro