crossing borders

When you have a "friend" sleeping in bed with you and you are "crossing borders" by having sex, feeling eachother up, etc. you on one side, your "friend" on the other. then you cross borders, that the girlfriend sets up, and "do it". usually tiedown free.

Danny and Jade wanted a little fun, but Jade didn't want him crossing borders.... He did anyway, now she's knocked up.