You share clothes and jewelry with your friends. So why not that flattering-on-everyone lipstick you love…right? Wrong very, very wrong. Sharing your favorite lip color with your beside could lead to something nasty and we’re not talking about getting upset when she doesn’t return it to you. “Sharing makeup with a friend comes the risk of infection,” says David Bank, M.D., a dermatologist in Mount Kisco, New York. “In sharing eyeliners and lipsticks, you can run the risk of contracting viral infections such as conjunctivitis and cold sores.” Oh, and one Australian woman claims she got a staph infection that has left her in a wheelchair permanently from using her friend’s makeup brush.