Megan announced she and Wes had "decided to separate" last weekend after less than a year together.
The pair met on Love Island's latest series on ITV last summer but recently faced relationship turmoil as Wes joined Dancing On Ice.
Megan lashed out at his pro partner Vanessa Bauer in a rant on social media, before revealing that she and Wes are no longer together.
Sources have now claimed the main reason behind the split was the pair's relationship getting "very intense" in a short period of time.
"Their relationship moved too quickly – they couldn’t keep up with it," the insider alleged. “One minute they were on a show together and the next Wes is moving out of his family home to live in a London flat with her."
They told The Sun newspaper: “It all became very intense and what’s worse is that their sex life started to suffer. As soon as Wes started to train for Dancing on Ice he became too tired for anything in the evening.
“There’s a four-year age difference between them too – that coupled with the threat of Vanessa and all the time her and Wes were spending together there was no hope.”
Despite the split - and her row with Vanessa - Megan appeared on Dancing On Ice on Sunday night to cheer on her ex.
She posted to Instagram before the show: "I will be down at Dancing On Ice tomorrow to watch him smash it again. Only one thing left to say, come on Wes and Vanessa! x"
Wes made it through the latest live show, with Dancing On Ice continuing Sunday nights at 6PM on ITV. He has yet to comment on the split.