Cute finale! Poor Haley and Andy... let's jump right in.
Alex has graduated from high school, and the whole family gets together at Jay and Gloria's house for a party. The whole family, that is, except for Phil, who got stuck out of town. He still manages to be at the party, sort of, by staying on a video chat on a rolling camera so he can move around and communicate with the whole family. Throughout the party, lots of shenanigans take place, with Phil trying to mediate all the chaos.
Mitchell and Cam have plans to buy the unit above theirs and expand their home, but Cam notices that Mitchell doesn't seem too excited. We learn that Mitchell has actually lost his job, and has been going to the park during the day and hanging out with an old man named Spencer. He didn't tell Cam that he lost his job, and now he wants Phil to help him so that they don't have to buy the unit upstairs, because they can no longer afford it. Cam is suspicious of Mitchell's behavior, and when he sees texts from a guy named Spencer on his phone, he thinks Mitchell is having an affair. When the truth comes out, Cam is just relieved that Mitchell hasn't been unfaithful, and they decide they'll buy the unit upstairs anyway. They can rent it out for now - it's still a great opportunity. Also, during all of this, Cam has been having trouble with his speech, because he got adult braces.
This plot thread didn't really do much for me. The braces thing was funny for a second, but it actually just got really annoying to hear Cam talk with a lisp. They purposefully wrote his lines with a lot of "s" words to really emphasize the impediment, and it felt sort of childish. Also, it's pretty horrible of Mitchell to hide such a huge secret from his husband, and I feel like the episode didn't really address the more serious aspects of Mitchell's mistakes. However, there were a few cute moments, like when Cam read Mitchell's phone through the bottom of a glass table.