AshleyMadison.com -- the website for people looking to have an affair -- has been hit by hackers who are threatening to expose personal information of more than 37 million cheaters.   

The site's parent company, Avid Life Media, confirmed the hack to KrebsOnSecurity.com, saying they've now secured their websites and are working with law enforcement to nab the culprits.

The hackers want Ashley Madison and another website, Established Men, taken down ... or else they'll release "all customer records, including profiles with all the customers’ secret sexual fantasies and matching credit card transactions, real names and addresses, and employee documents and emails."

Prepare your excuses now ...