During his time on the reality TV franchise, Laundy was still legally married to his estranged wife.
The millionaire publican made light of the situation, comparing himself to Monk's new beau, saying: "If her track record is anything to go by, she's on to a good thing. But you'd have to call me a little bias."
Stu further confessed it was "fantastic news" and said he'd love to officiate the day.
He shared, "'I will always have feelings for Soph. She's a lovely, lovely human being, but we weren't meant to be. I hope we are always friends."
The reality TV couple broke up at the beginning of the year.
In an emotional Instagram post, Monk said she gave the relationship her “best shot” but it “just didn’t work out” because the two were “very different people”.
“I went into this experience looking to settle down and start a family,” she wrote.
“I gave it the best shot I could and my intentions were everything, but unfortunately it just didn’t work out. As much as I respect him we are just very different people.”