Casey Affleck congratulates Ben and J.Lo after skipping their wedding: 'Welcome to the family'

Casey Affleck is welcoming Jennifer Lopez to the family — via social media — after missing his brother Ben's Georgia wedding due to "parental obligations at home."

Alongside a throwback of the the three of them together when Ben and Jennifer first dated, between 2002 and 2004, Casey posted a message to his new sister-in-law on Instagram which was both sentimental and playful.

"Good things are worth waiting for," Casey began. "Here is to twists and turns, new beginnings, and finding new reservoirs of old love. Welcome to the family. Get ready for some real dysfunction! Kidding. I am kidding. Jen, you are a gem. We love you so much!!!"

Much was made over why Ben's only sibling wasn't at the wedding, held at Ben's Riceboro, Ga., estate. Casey was photographed leaving a Dunkin' Donuts in L.A. Friday with his girlfriend Caylee Cowan. He was photographed in L.A. on Saturday as well. Asked by a TMZ cameraman why he wasn't at the wedding, he reportedly quipped, "I fell asleep."

A source told People magazine that Casey missed Ben's wedding Saturday "unfortunately because of family, parental obligations at home."

Cowan defended Casey in the comments of his post about Lopez, a message that now seems to be deleted. She wrote Casey had to take his 14-year-old son, Atticus, to soccer practice the day of the wedding. He also shares a son Indiana, 18, with ex-wife Summer Phoenix.

"Hey, if you weren't in town Saturday to take Atty to soccer practice then who would have helped the kid who broke his arm? You're a good man. I love you."

Soon after Casey's tribute to the bride and groom, he posted a throwback of his older son, Indiana, and a message suggesting the 18-year-old was headed off to college — or another adventure taking him away from home.

"Though a ship is safest in harbor, that is not what ships are made for," he wrote. "You are ready for this. You are uniquely wonderful, full of integrity, courage, and kindness. You will be an improvement to the land of 'grownups.' And if you go out into the world with curious amazement and sincere gratitude, the world will (eventually) meet you with the same. But please remember that one of the best parts of any adventure... is coming home. I will always be here for you. I love you."

Ben and Jennifer said "I do" for the second time on Saturday after eloping in Las Vegas on July 17. The 87-acre compound outside Savannah was reportedly where they were supposed to marry the first go-round, in 2003.

Saturday's ceremony was attended by Ben's pal Matt Damon and his wife Luciana Barroso, Clerks director Kevin Smith and his wife Jennifer, Clerks star Jason Mewes and his wife Jordan Monsanto as well as talent agent Patrick Whitesell and his wife, model/actress Pia Miller.

The newlywed's combined brood — her 14-year-old twins, Max and Emme, with ex Marc Anthony and his three children with Jennifer Garner (Violet, 16; Seraphina, 13; and Samuel, 10) — were there as well.

During the pre-wedding festivities, Chris Boldt — mom of Ben and Casey — reportedly fell off the dock and cut her leg. She was rushed to a local hospital via ambulance for stitches with Ben and Jennifer pictured visiting her before festivities began.