Plot summary
Molly invites Peggy to join her for a post-book trip, but Peggy's usual coldness towards the idea results in an argument where Molly says how terrible Peggy is but then leads to Peggy having a heart attack. Mike sides with his mother in her dispute with Molly and points out that she's always been negative and mocking towards Peggy. Molly admits she loves Peggy, and Peggy later tells Molly that she was not responsible for her heart attack but didn't understand why Molly didn't consider her a friend by now. Molly then confirms that she is Peggy's friend.
Credits
Adapted from Wikipedia contributors, Mike & Molly season 6. HTML formatting and reference markers removed.