Brett Heady is an Australian Football Player who played in the Australian Football League aka AFL.
In Australian rhyming slang, when a male receives oral sex it is called Brett Heady.
The equivalent to performing oral sex on a female in Australian rhyming slang is Greg Rowell aka go the growl.
Knighty: So I took that stinker Tara out for date.
T-Dawg: Yeah, so how'd it go, you get some?
Knighty: Nothing, dropped 150$ on meals and movie.
T-Dawg: Not even a bit of Brett Heady?