Argent made the revelation on last night's TOWIE, denying rumours circulating among the cast that he had cheated on Bright during their four-year romance.
Speaking to friends Joey Essex and James 'Diags' Bennewith, Arg joked that he would probably still be a virgin if he hadn't met Bright.
"At least one good thing came out of the relationship. I lost my virginity to Lydia," said Argent.
"I'd probably still be a virgin now."
When Essex mocked his pal, Arg added: "Shut up, you weirdo. I went out with her for four years, you doughnut.... Sympathy, though. Cheers boys."
Meanwhile, Essex and Diags attempted to start a new relationship on the scripted reality show by double dating Lauren Pope and Georgina Dorsett.
TOWIE continues on Sunday night (February 12) on ITV2.
> 'TOWIE' Joey Essex takes shine to newcomer Georgina Dorsett
> 'TOWIE' Lydia Bright on James Argent: 'I could kill him'