Frog sex just got a whole lot kinkier.

All of the world's nearly 7,000 known frog species mate in one of six different positions: Most involve the male grabbing the female around the waist or under the armpits in a mating "hug" called amplexus. 

This special embrace helps the male and female get close enough so that his sperm fertilizes as many of her eggs as possible. But it's still pretty tame. (See "How Female Frogs Get Tricked Into Choosing An 'Ugly' Mate.")

The Bombay night frog of India, however, hasn't gotten the memo—the amphibian mates in a never before seen position called the dorsal straddle.

Instead of releasing sperm near the female's cloaca, or all-purpose hole, the male Bombay night frog ejaculates on his partner’s back. The sperm then trickles down and fertilizes her eggs, according to a new study published June 14 in the journal PeerJ. 

Not only that, they don't use amplexus at all—instead, the