Greg was overcome with emotion in the clip as his groomsmen said a prayer on his behalf.
When Greg walked off and attempted to hide his face after the prayer, a friend asked him, "Are you happy or sad?"
"No, I'm happy," Greg replied in tears, trying to hold it together.
Greg's friends advised Greg to let it all out before the wedding and just be his authentic self in his upcoming marriage. They had his back and hoped for the best for him.
On Unfiltered, Greg laughed about how he knew producers were going to edit that scene into an episode of Married at First Sight.
After Greg joked it was hot in that room, the sun was in his face and he probably had allergies, which were excuses as to why it just looked like he was crying, Pastor Cal chimed in a more serious note.
"That's why we chose this guy," Pastor Cal said proudly of the Season 9 participant.
And then Greg explained why he got so teary-eyed before his wedding.
"[I was feeling] a lot of emotions. I always wanted to get married and wanted to be that true husband and be that person," Greg said.
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"But there were just a lot of emotions, like having my good friends there and being a man of faith and having that prayer over me and over my marriage and over my wife, it just got to me."
Pastor Cal gushed about how he was "so impressed" with Greg and it made him "feel good to know that we chose the right guy."
"When Greg's name came up [in the matchmaking process], we said, "This guy has got values, he has heart, he has sincerity, and we know he wants this. And so he was an easy choice. He was a very easy choice."
In addition to Pastor Cal, Greg and Deonna had been matched to marry by Dr. Pepper Schwartz as well as newcomer Dr. Viviana Coles, a psychotherapist who replaced Dr. Jessica Griffin for the new season.