Just a few weeks ago, Made In Chelsea star Sam Thompson and Zara McDermott looked happier than ever on a romantic post-lockdown holiday in Mykonos. Now, though, it looks like the reality power couple have split for good after Sam reportedly discovered that Zara had been unfaithful to him during her time on Celebrity X Factor last year. According to a source who spoke to the MailOnline, ‘Zara cheated on Sam with someone in the music industry. Someone connected to the X Factor. Sam is obviously distraught about this. He only found out about it very recently and has escaped for a few days. Zara regrets it and feels terrible. She knows it was a huge mistake and is extremely upset.’Zara appeared on Celebrity X Factor as part of Love Island super-group No Love Lost between October and November 2019. Her bandmates were fellow former Islanders Samira Mighty, Wes Nelson and Eyal Booker. The show was judged by Simon Cowell, Nicole Scherzinger and Louis Walsh and featured guest judges including Tricky Stewart, JC Chasez and Randy Jackson. Sam's sister Louise also seems to have gotten involved in the drama, tweeting earlier this week 'Cheaters always want you to be loyal while they're being unfaithful'. Whilst fans originally worried this meant trouble in her own relationship with Ryan Libbey, it now seems she was throwing shade at Zara, who had a meltdown on Made In Chelsea last year when Sam was friendly with his ex Tiffany Watson. Aside from the cheating rumours, it also seems that the pressures of lockdown took their toll on Sam and Zara’s relationship. Despite plenty of gushing social media posts over the last few months - and even talk of marriage - a source told the Mail Online that the couple ‘had been arguing a lot since moving in together’.