Ellie apparently even told her ex she loved him just before flying out to Spain for the show.
The 20-year-old Business Development Manager from Newcastle joined Love Island earlier this week as one of two new bombshells.
But a source told The Sun newspaper: "Ellie had a really nice boyfriend, he’s a successful businessman. They broke up in December but started seeing each other again two months ago. They kept it really low key but they were spending a lot of time with each other.
“Everyone thought they seemed really happy together. But then the next thing we know she’s in Love Island – and he’s back home watching her on TV. It’s crazy. She’d even said she loved him.”
However Ellie's pals have defended her and insisted she and her ex had never got back together.
"Ellie had seen him around because they have mutual friends but they weren't dating. She's been single ever since their break up," they told the tabloid.
Since entering the villa, Ellie has got close to Alex George but Samira Mighty doesn't trust her.
In tonight's (Friday) show, Samira tells Alex of Samira: "I don’t trust her. She’s just not certain of things and if you come in here you want to be certain. I just don’t know her intentions in here, but it’s fine, she’s young.
"Not genuine, as in genuine about you. Because she hasn’t put any effort in.”
Love Island 2018 continues nightly on ITV2.