A man positions himself behind his partner, and inserts his d*ck into his woman's vagina from behind. She's usually bending oversomething, or on her hands and knees. The guy can then pull her hair, and use her boobies for handles.
When a man stands on his partners face with either his left or right foot while riding her in doggy style. It takes a certain amount of flexibility and balance, but definetely one to brag about.
Me: I heard Paul fucked some chick reverse doggy style last night.
Justin: Really? I didn't think his dick was big enough for that.
Me: You're probably right. He's gotta be lying.