Picture this: your spouse brings home someone you have never met before, or know only superficially and encourages you to go play. The new person (we'll call them Alex for convenience of antecedent) is "about your age" and your gender, clearly two key components for getting along. Alex proceeds to touch all your belongings and treat them as if they are her own. She logs onto your computer and checks email, surfs the web and tosses the keyboard aside when she's done. She then proceeds to go into your bedroom, try on your favorite skinny jeans (damn if she doesn't look better in them than you do!) and drinks your last Diet Coke. You try to occupy yourself with other things, but feel increasingly anxious as Alex rifles through your other belongings looking for something fun to do.
Just as you are about to post a giant "Don't Touch! It's Mine" sign in each room, you find her on the couch, watching one of your favorite old movies. At last! Common interest! You share a chuckle and settle in just as your spouse looks at his watch and announces it's time for Alex to leave.
2 hours of discomfort for 5 minutes of joy.