"One of the most beautiful weddings for the most beautiful bride," Kelley, 30, captioned her picture from the lavish affair in Dallas, TX, adding Madison's "It's About Troutt Time" wedding hashtag to her post.
Peter, 31, quickly commented on Kelley's post, "Where's Peter," pointing out how his girlfriend attended the wedding solo.
Kelley promptly replied with a firm, "Peter Christian," seemingly scolding the Season 24 The Bachelor star.
"You know when that middle name gets pulled out," Kelley joked of the pilot's first and middle names. "Get to bed."
Peter, however, didn't back down so easily, writing on social media, "I'm in trouble... You look beautiful, night."
After Peter's romance with his Season 24 winner, Hannah Ann Sluss, didn't work out, he had a short-lived romance with Madison -- his The Bachelor runner-up -- before pursuing a relationship with Kelley, his fifth-place finisher on the show.
Madison was torn up over the fact Peter had been intimate with one or more of his other finalists.
Peter and Madison also constantly questioned if their relationship could make it long-term due to their different lifestyles and motivations.
Peter's mother Barbara Weber claimed Peter loves to party and is generally "spiritual," but Madison claimed to have devoted her life to God.
She even graduated seminary school and had envisioned herself becoming a pastor's wife. (Madison's husband, Grant, ironically is an aspiring pastor).
Not only was Madison a virgin on the show -- and Peter had sex with Hannah Brown four times in the Fantasy Suite onThe Bachelorette's fifteenth season -- but Madison said she expected her future husband to be the religious leader of her future children.
Peter therefore proposed marriage to his last remaining bachelorette and technical winner, Hannah Ann, but then he called off his engagement to Hannah and asked Madison for a second chance.
Madison agreed to try again, but just two short days after Peter and Madison's joint appearance onThe Bachelor season's After the Final Rose special in March 2020, the pair released separate statements via Instagram announcing they had decided to split and end their revived romance.
Peter then moved on with Kelley, and they've had an on-again, off-again dynamic ever since.