Marine's son, 4, bursts into tears as dad, stepmom wed in heartwarming video

Joshua Newville and Emily Leehan may have gotten married in front of 130 of their closest family members and friends over the weekend — but it was Newville’s 4-year-old son who stole the show.

In a video that’s gone viral, the adorable boy, Gage, becomes overwhelmed and breaks down into tears of joy while his stepmom reads surprise vows she wrote just for him.

“I want you to be safe and to try your hardest and to be a good person,” Leehan tells Gage, who begins to cry and runs into her arms.

She adds, “I know that you and I will butt heads, except for right now. But I hope, with all my heart, that as you become a grown man, you will understand my methods and realize I've only done what is best for you and that I love you."

U.S. Marine Corps Sergeant Joshua Newville and Senior Airman Emily Leehan got married on Saturday in upstate New York. Newville's son, Gage, became overwhelmed with emotion at the ceremony.

"The last thing that I hope you learn is that you are a very special boy," she says.

"You are so extremely smart, handsome and kind to others. You have helped make me into the woman I am today, and I may not have given you the gift of life, but life surely gave me the gift of you."

Newville, who is a sergeant in the Marines, told TODAY, that he too was trying to keep it together at the alter.

“I was thinking ‘don’t cry’ and was just trying to comfort Gage," the 24-year-old said. "It truly means something when someone who has no involvement in creating Gage loves him as if she did. I was just very proud and happy and excited.”

He described Gage as an animated little boy who “wears every emotion on his sleeve.”

Newville, Leehan and Gage. "Overall, he stole the show for the whole day," Leehan said of Gage.

Newville and Leehan, a senior airman in the Air Force, met at the Joint Base McGuire-Dix-Lakehurst in Trenton, New Jersey, and have been dating for about three years.

Leehan said her wedding day at Quincy Cellars in Ripley, New York, was magical.

Gage, a huge Star Wars fan, again stole the show later in the day when he walked into the reception wearing a Darth Vader mask while the movie’s theme song played.