What's the position called when the girl is laying on her stomach, and the guy enters her vagina from behind?

It's lazy doggy!

I think that you're thinking of the "jockey" or "rear entry" positions.These are both awesome and it's one of my faves for getting anal from a guy.

apparently its just called "rear entry." what a boring name for such a good position! :(

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Its my favorite too...i cross my legs and it makes it feel better for me and the guy.

Sounds like some kind of Kama Sutra sh*t to me.

Inverted Missionary is when the girl is lying flat on top of the guy, rather than the dude on top of the girl.

Downward Dog is a yoga position...

Spoons is side ways...

According to a website it's called "Acrobat", then again I could be totally wrong.

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^ is that what you're talking about?

Isn't that like the inverted missionary or belly flop or something like that? dunno..don't think there is like a real name for it!

I have heard it called the "downward dog" before. =P

It's a rear-entry position. Make up a name that suits you.

this is a common variation of the spoons position-some women like it because the weight of the guy they are with is not all over them and they can concentrate on their and your **** sensations better---so enjoy!-it can also be done laying on your sides and can even go into a scissors type position as well

I think its called spooning. I like doggy style better.