Friends: 10 Reasons Why Ross Is The Worst Person Ever
4. His Relationship With Mona
Ross met Mona (Bonnie Somerville) at Chandler and Monica's wedding, and the pair hit it off, eventually developing a relationship. A relationship, that is, built on lies and neglect, as Mona is sidelined by her new "boyfriend" and constantly forgotten about and messed around.
First, Ross proves incapable of talking about his feelings with her about their relationship. Then, he gives her the only key to his apartment and has the locks changed so he can get some keys made. He forgets about date nights because of Rachel's pregnancy, and, to top it all off, doesn't even mention the pregnancy to her whilst they're together, something he should have done as soon as possible.
Sure, he had a lot on his plate, but Mona was a genuinely nice (if underexplored) character who never deserved to be so royally screwed around by a guy who didn't seem to care about her in the big moments.