Inside the wedding for the man who proposed to 2 sisters for a very touching reason

He vowed to love one and be best friends with the other.

— -- Ashley Schaus and Will Seaton wed last week after their story captured hearts this past summer.

When Seaton proposed marriage to Schaus, he also proposed best friendship to her sister, Hannah Schaus, who has Down syndrome and diabetes. He gave both sisters rings.

"I told him we were a package deal when we started dating in 2010," Ashley Schaus told ABC News.

Hannah Schaus told ABC News that Seaton is "amazing" and said his decision to include her in the couple's special proposal moment made her "very happy."

At the wedding, Seaton and Hannah Schaus promised to always take care of each other.

The trio walked into the reception together.

Ashley Schaus told ABC News that her sister smashed cake in her and Seaton’s faces.

The newlyweds danced to "Soul Mate," while Seaton and Hannah Schaus fast-danced to “You’ve Got a Friend in Me.”

Ashley Schaus said she’s thankful that Seaton is her soul mate and such a good friend to both her and her sister.