Tear Jerker / Beverly Hill 90210

• Brenda learning that Dylan cheated with Kelly (Season 3's "Back in the High Life Again"). Even though Brenda knew Dylan had an affair with someone during the summer, she didn't know who with. When Kelly revealed that she was the one, it was the ultimate betrayal. Brenda losing her boyfriend to a person whom she thought she could trust, which could easily connect with viewers who had a similar experience, and also goes to show that betrayal is never at the hands of your enemies. It doesn't help that Dylan acts very blase about it, though Kelly tries to soften the blow, though Shannen Doherty's performance speaks volumes.
  Kelly: Neither of us wanted to hurt you.
  Brenda: You didn't care how I felt at all, Kelly!
  [...]
  Brenda: Look, I hate you both. Never talk to me again!
  • After the death of Dylan's father, Brenda puts aside her anger to invite Dylan to stay with the family so that he won't be alone.
  Brenda: Years from now, your dad will still be gone and I'll just be some girl you knew in high school.
  Dylan: (tearfully) No, you won't, Brenda. Not after everything.
  (They hug, and Dylan's remorse for hurting her and relief that she's beginning to forgive him is palpable)