1x13 - Pepper Dennis

In the series finale, Pepper finds herself walking down the aisle after a surprise proposal from Babcock. But the whirlwind wedding isn't as romantic as it seems: Charlie's green card has expired, and a government agent, suspicious of the sudden nuptials, is ready to deport him back to Canada. Pepper and Babcock try to convince him that the marriage is genuine, but real feelings emerge, causing one of them to get cold feet.