1. You're woken in the night at the sound of their orgasmic crying out of another's name, as they thrust their hips up and down lustily.
2.They become overly interested in your best friend, wanting to help them with jobs they flatly refuse to do for you.
3. It takes them four hours to buy a newspaper.
4. They keep on calling you by different names.
5.She comes home with leaves in her tights.
6. They disappear into your friend's van which is parked outside your house and bounces up and down for fifteen minutes or so. They come out looking disheveled, and claim they were checking the suspension.
7.They encourage you to go out with your friends every night, and on holiday with them, for as long as possible.
8.You catch them staring into space with a glazed over look in their eyes and saliva dripping from the corner of their mouth.
9.They can't stop talking about how marvelous so and so is, regarding everything.
10.They become obsessed with basket weaving and ping pong and dress seductively to attend four or five times a week.
11.You find their underwear in the car, in their pocket, stuffed behind a radiator, down the sofa and a stranger's hairs in your bed.
12.They want your homeless, jobless friend to move in as a lodger and insist on taking them breakfast in bed before you leave for work and are still in there when you get home.
13.They stare at the other person even when they're talking to you, and, then you notice how they give each other knowing looks, flirty, come ons all night.
14.Your friend offers to teach them massaging techniques and they readily agree, they both spend the next ten hours in your bedroom emitting numerous prolonged groans.
15.They become obsessed with their physical appearance, especially when they won't be spending any time with you.
16.They claim to have a head ache, every night for five years, but, refuse asprin or paracetamol.
17. They go on holiday alone but won't show you their photographs, and stay up at night looking at them and kissing them longingly.
18.They hear nothing you say, have no interest in you except as a babysitter.
19.They won't let you read their emails or texts.
20.Monica Lewinski. Need I say more? And lipstick on your collar!