When your about to have sex with a woman doggy style and the woman has a fat ass. To reach the pussy you must lift up her butt cheeks and fly under the radar to have sex. This can also happen when a woman have a f.u.p.a and you have to lift the f.u.p.a up to reach her pussy.
Greg: Dude your girlfriend has a fat ass! What is that like when you bang her from behind?
Jack: Well I have to Fly Under the Radar to reach her pussy.
Greg: Oh My God.
When a woman that wants to have crazy sex with you but she lives to far away. By taking care of business you travel to the woman's location and fuck the shit out of her.
George lived 2 hours away from Jill (a girl he met at college) and Jill really wants to have sex with George. George decides to take work off so he can go "taking care of business" and travel the 2 hours to fuck Jill.