On the first day of Gavin Graves' wedding, the bride died, and her replica was sent to the hospital.
On the second day of the wedding, the replica took the bride's place and sat on the spacious wedding bed watching My Little Pony all night.
The third day was the day of returning home, and Gavin Graves went to the Richards Family house alone. The bride didn't go because she couldn't get out of bed after watching cartoons all night.
Actually, not many people care about returning home on the third day anymore; this time is a special case. Rather than calling it returning home, it's more like attending Zenaida Richards' funeral.
Yes, the person in the coffin was the elder sister Madison Richards, but it was under the name of the younger sister Zenaida Richards that she was buried.
As the new son-in-law, no matter how grand he was usually, Gavin still had to show this bit of respect to the Lawson Family.