Jennifer Lopez Gives Slapping Lessons to Jane Fonda  4/16/05

Jane Fonda took slapping lessons from her Monster in Law co-star Jennifer Lopez after striking her several times in rehearsals.

Fonda and Lopez play warring females in the movie and have one scene where they literally just slap each other.

And Fonda admits she had to take advice from Lopez after constantly missing her mark and connecting with J.LO's head.

Fonda says, "Jennifer, who is a dancer, is very adept at physicality. A couple of times in rehearsals I almost hurt her, so she directed me and it was too cool.

"She told me what to do and where I can throw my arm or throw my body so that it would look good but it wouldn't really hurt her. Doing these kinds of things with her was really easy and a lot of fun."