My lab is a perv, and all he does is "dance" with any dog that comes in the house, and with Tanzy all the time. He's 4 and he's been fixed since he was around 1.
Tanz has picked up on it, but she only does it to my friends Rottie (who is 105lbs at 9months!) it's pretty funny to see her trying to do that to him, considering he is more than 3x her size. Ugh!