The former TOWIE star confessed he and Michelle, both 27, haven't even discussed the possibility because they trust each other so much.
He told the Mirror: "I see why people do [discuss it] because of what's happened in the past.
"But if you're in a genuinely happy, strong, beautiful relationship it just doesn't enter your head. It's never been a question for us, genuinely."
Mark may have to dance with the beautiful Karen Hauer but he insists Michelle is not bothered at all.
He continued: "We're a happy couple who trust each other. We don't think about, 'Oh, can I trust him?' or 'Can't I trust him?' She's just like, 'Enjoy it, babe – she looks like a great partner'. And that's it."
And Mark showed just what he's like as a fiancée this week when Michelle posted her envy of the Victoria's Secret girls on Twitter.
Actress Michelle joked that the models should've been motivating her to get to the gym.
Mark then shared a picture of his stunning wife-to-be in a bikini, writing: "Something tells me they say the same about you @michkeegan [sic]"