As the wedding is finishing up and Mike and Susan are kissing, Katherine's banging on the closet door, finally knocking it down. And if you thought she was pissed before, you should see her now. This is her, "Sorry I'm late" moment from the beginning of the episode. Mike asks what she's doing here, and she's like, "Susan knows." Mike doesn't know what she's doing here, but he's asking her nicely to leave. Because he's so nice, he adds that if she doesn't, he'll drag her out of this church himself. She gets teary and says she's sorry; she'll go. But Susan tells her to wait, and she runs back to the microphone. She says she just wants to say something. Then she motions to her videographer not to capture this part, please.
She says the day Mike asked her to marry him, AGAIN, was the happiest day of her life. AGAIN. (Okay, so she might not have said that second again, but everyone was thinking it.) But for someone else, it was the day her whole world fell apart. She looks at Katherine, who's crying. Susan admits that she didn't care, because, "In that moment, I was a selfish person." In that moment? That's an interesting interpretation of herself, isn't it. Susan said she chose her happiness, but she is truly sorry for changing Katherine's path. Well, technically, she didn't change it herself or anything. She hopes Katherine Mayfair finds happiness and can find it in her heart to forgive Susan. She arrives to Katherine and lowers the mic, adding, "... and be my friend again." Katherine hugs Susan, who says, "I hope that helped." Katherine whispers: "Honestly. It didn't." She leaves and Susan smiles knowingly, like, "Well, she got me."