Many a couple shares bad habits that outsiders might consider strange at best and disgusting at worst. When I recently watched an episode of How I Met Your Mother and the characters discussed sharing a toothbrush, I was horrified. I feel toothbrushes are personal items, and I don't share mine with anyone, not even my husband. Apparently, other couples don't feel that way. It got me curious about whether sharing a toothbrush could pose health risks or is just yucky. It turns out it's basically just yucky. Anyway, this led to curiosity about other gross couple's habits. You can find out just how gross you are by reading this story about all the icky things couples start to do after they get too comfortable with one another.