get some leg
Get some sex from a female. This isn't up for debate, the term has been around for a long time and it's in the dictionary. No it's not "legs" plural, just leg. Leg is a euphemism just like "get some ass" where leg and ass are the stand in for vagina. To have sex. Women sometimes use the phrase to, because they think it's cute to use men's phrases.
"You´ll get some leg tonight for sure! Tell us how you do! " ~ Van Halen, from "Unchained"
Get some legs
To have sex with a woman and thus get the pussy between her legs.
I'm gona get some legs tonight.
Get some leg
To get some ass.
Eddie Van Halen: Hey man, that suit is you!
Woo-whee! You'll get some leg tonight for sure!
Woo-whee! You'll get some leg tonight for sure!