This just in: An invoicing mistake can mess up a whole lot more than a company’s records.

Lynn Newby, of Rotherham, England, was going through her usual practice of doing a line-by-line check of online purchases on her Tesco ClubCard. Everything looked fine, until she saw an unusual purchase at the top of the list: a 12-pack of condoms.

Newby jumped to the conclusion that her boyfriend of four years was having an affair (but still used the online rewards card, because who doesn’t love a discount?). After printing out the list and confronting her boyfriend, he swore he had no idea where the purchase came from.

She was on the verge of cancelling vacation plans — that is, until a co-worker informed her the same mysterious charges had popped up on her online account, so there must have been an error on Tesco’s behalf (unless both significant others were in cahoots, of course).

According to Tesco CEO Terry Leahy, the condom purchase was mistakenly added to hundreds of accounts when a new employee incorrectly inputted info about a promotion into the company’s systems.

To make up for the error, Tesco sent $200 and a letter of apology to Newby and her boyfriend.

Tags: Accounting error, Invoicing, Line-by-line, Online rewards, Tesco