The Olympic athlete made the claim after he became the latest person to be dumped from the Love Island villa.
When asked which couples he thinks will go all the way and win the show, the Blazin Squad star and Gabby were amongst three couples Theo tipped for the final.
He said: “After taking Jamie under my wing, I think him and Camilla have the potential to win because they are the most genuine people you’ll meet. Same goes with Marcel and Gabby, they are up there as well. I’m going to say they are going to be the top two couples.
“I like Liv and Chris the best in there, they are my favourite couple. I hope to see all three couples in the final but whoever wins will deserve it.”
Love Island: Theo Campbell made the claim about Marcel Somerville and Gabby Allen [ITV]
The star then went on to say that he believes that Marcel and Gabby are a genuine couple, adding: “The real deal couple are Marcel and Gabby,
“They’ve been fortunate enough to not really be tested in the villa. They have had it nice and easy.”
But after making the slight dig at the popular couple, Theo then suggested that the two could go on to make their relationship seriously official by getting engaged.
When asked who he thinks will be engaged this time next year, he replied: “I could imagine Marcel asking the question to Gabby!”
If Marcel does pop the question to Gabby, they’ll be the third Love Island couple to get engaged.
In series one, TOWIE star Jon Clark popped the question to Playboy model girlfriend Hannah Elizabeth after a whirlwind romance in the villa.
Love Island: Gabby Allen and Marcel Somerville could be the next couple to be engaged [Wenn]
Love Island: Theo Campbell predicted Gabby Allen and Marcel Somerville could get married [Wenn]
While last year saw Alex Bowen and Olivia Buckland get engaged, with the couple’s nuptials coming soon.
So will Marcel and Gabby make it all the way to the alter?
Upon leaving the villa, Theo also took the opportunity to blast Tyla Carr, branding her “fake”.
He revealed: “I do believe Tyla is very fake, She has a game plan and an agenda and that’s going to be proven. I’ll be proven right.
“She was so hysterical and was crying so much but if she really cared that much she would go as well. Her putting on these crocodile tears was annoying me so much!
Love Island: Tyla Carr was blasted by Theo Campbell [ITV]
Love Island: Theo Campbell accused Tyla Carr of being fake [ITV]
“Obviously she was never going to go and now that Mike [Thalassitis] is in the house we’ll see how much she really did care about Jonny.”
Love Island continues at 9pm on ITV2.