I watched an episode once where they found a woman's hair on a guys jacket and were like "she must be your girlfriend" and I was like "I find my roommates hair on my bra on a regular basis. You obviously don't understand how women's hair works."
"I'm on my period & today I bled through to the couch. When I noticed I started freaking out & my boyfriend told me to go get cleaned up & he would take care of it. When I came back the stain was gone."