The reality star, 23, took to Twitter for a rant on Monday afternoon (12 August) and although she didn't specifically say who her tweet was aimed at, fans believe it could be Charlie as she says it's about someone she is in love with.
Her tweet came after Charlie was pictured getting close to a blonde bikini-clad woman while on a lads' holiday to Ibiza last month, in an incident that angered Ferne's best friend Sam Faiers.
Sam tweeted a link to the story with the caption: "I cannot believe BOYS... I'm disgusted!!!! Makes me sick."
The state of Ferne and Charlie's relationship has been a bit unclear since then as neither has expressly mentioned the incident, but Charlie did send Ferne a 23rd birthday message via Twitter last week.
The couple, who have been together for three years, were also seen out in London over the weekend watching The Bodyguard musical and then enjoying dinner.
Today, however, Ferne tweeted: "I have never come across such a mean, cruel, insensitive boy! You think you know someone, you think your madly in love. Complete asshole!"
The reason for her tweet – or if it is definitely aimed at Charlie – is unclear.
I have never come across such a mean, cruel, insensitive boy! You think you know someone, you think your madly in love. Complete asshole!— Ferne McCann (@fernemccann) August 12, 2013
Among those who responded to Ferne's message was ex-TOWIE star Maria Fowler, who wrote: "They never fail to shock men don't. Hope you're ok x x."
Ferne had appeared in good spirits at the weekend when she celebrated her birthday with friends and family looking gorgeous in a white dress.