Friends: 10 Worst Things Monica Has Ever Done

In “The One With Phoebe's Husband”, Phoebe turns out to be married to Duncan, a gay friend from Canada who just needed a green card. However, she was in love with him. After six years, Duncan is back and needs a divorce. Turns out he's not gay and is getting married to someone else.

Monica got upset that Phoebe didn't tell her she got married, so this secret prompted several other discoveries. Phoebe tried to manipulate Monica and revealed that the underwear on the telephone pole outside is Monica's, from when she had sex with Fun Bobby on the balcony. Monica understood that it was Chandler who disclosed her secret. So, being very upset, she retaliated by revealing that Chandler has a third nipple.

Although it is not shown in the entire series how Monica knew about Chandler’s third nipple, fans can assume that Chandler told her about his deepest secret as they were closer than the other friends. Ross seemed somewhat surprised by this fact, even though he probably has seen it before since they were roommates in college.

This then became a periodical joke on the show, with the others constantly ribbing and humiliating Chandler about his condition until he had it removes after his date Ginger with the wooden leg freaks out.