The line

Where is the line in relationships? When does your partner become the 3rd wheel? Is it okay to ask them to back off so you can have a day to your self? Or with someone else? When can one go "Honey I need "me" time" or "Babe, I am going to hang out with an old friend. Alone." Is that okay? I mean can you not always be attached? When you enter a serious relationship is it than forever a package deal?