1
general::
Phrase(s): lie with someone
1. to recline with someone. • Come and lie with me and we will keep warm. • Jimmy and Franny were lying with each other to keep warm. 2. Euph. to recline with someone and have sex. • She claimed he asked her to lie with him. • Do you mean to imply that she lay with him?
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Be decided by, dependent on, or up to. For example, The choice of restaurant lies with you. Starting about 1300 this phrase meant ‘‘to have sexual intercourse with," a usage that is now obsolete. [Late 1800s]
American Heritage Idioms