The Big Bang Theory Season 10 Episode 1
The Conjugal Conjecture
Penny and Leonard are trying to sleep, but Sheldon is concerned about whether or not he and Leonard could become brothers after realizing that his mother spend the night with Leonard's dad.
Beverly arrives to the apartment and says she won't go to the wedding, but they convince her she shouldn't let it get to her.
Meanwhile, Howard gets a mysterious visitor, but Raj gets nervous when he answers the door and lies to say Howard isn't there. Howard calls later and sets up a meeting to find out what the man wanted, but it's still a secret.
Penny picks up her family, including her brother, Randall, who was recently released from prison (played by Jack McBrayer).
Alfred and Mary say they already have plans to visit one another, and Sheldon insinuates that Alfred isn't good enough for his mother. That, of course, upsets Leonard.
Penny's mother is nervous about meeting everyone, concerned they will think their family is white trash.
At the wedding, everyone is still bickering until Bernadette shuts that down. Penny and Leonard exchange vows in a sweet moment, and Sheldon speaks up to say how special both of them are to him.
Leonard's parents get along just for a moment when they agree there was one good thing that came from their relationship: Leonard.