The fallen popstar allegedly flew into a rage, throwing the Birmingham-born photographer's iPhone into her pool after discovering the suggestive messages.
An insider told The Sun: "There were about a dozen (texts) from one girl, all sent in one day. They were pretty saucy stuff with sexual references - certainly not the sort you'd send to a friend.
Dumped: Adnan's apparent text flirting is the final straw for Britney
"Britney lost it and started yelling. She was demanding to know who sent the texts and shouting, 'What's this about? You're cheating on me.'
"Adnan said she was just a friend but Britney got more and more angry. Then she told him, 'That's it. It's over.'"
But the break-up was not the only bad news for Britney.
The "Toxic" singer could lose her millions within four years if she does not curb her urge to spend.
The singer, who was previously worth £50million, now has an estimated bank balance of £20million due to shopping sprees, holidays and partying.
This sharp decline in her wealth is also reportedly due to spending huge chunks of her savings on houses and cars.
Shopping in Beverly Hills: Britney's spending sprees have cost her a reported £30million
According to the Daily Star, the 26-year-old's mother and father, Lynne and Jamie, are now in crisis talks with the star over her financial recklessness and its consequences.
A Spears' business associate said to the tabloid: "She was very wide-eyed and attentive but she's as addicted to buying houses and new Mercedes as she is to the attention of the paparazzi.
"There was a moment when her mother said she could be out of money within four years and her children would still be in primary school."
"That was when she really sat up and took notice."
