Heidi Klum has spoken out for the first time since her divorce from Seal turned nasty when he accused her of “fornicating with the help,” insisting, “When we were together, I never looked at another man.”

The German supermodel and TV host broke her silence in an exclusive TV interview with Katie Couric, recorded last week. The interview will be broadcast on Couric’s new daytime show, “Katie.”

Sources tell us Klum was devastated after Seal made the mean-spirited comment, which suggested his ex-wife’s alleged cheating with her bodyguard caused their split. Seal told TMZ just over a week ago, after news of her becoming close to bodyguard Martin Kristen broke: “I preferred Heidi would have showed a little bit more class and at least waited until we separated first before deciding to fornicate with the help.”

While she has become close to her bodyguard of four years, friends insist this has happened only since her split from Seal. The pair separated in January and filed for divorce in April after nearly seven years of marriage.

The “Project Runway” host and hunky Australian Kristen were spotted in New York a few weeks ago and on the beach in Sardinia with her children. Seal also added in an interview with TMZ, “I guess you now all have the answer that you’ve been looking for the past seven months.”

Hinting that British-born singer Seal had used strong words during their marriage, Klum told Couric about Seal’s comments, in an excerpt revealed exclusively to Page Six: “It was a unique choice of words . . . I’m used to it. Other people aren’t. When we were together, I never looked at another man.”

We’re told that Klum, who also said she was trying to mend her friendship with Seal, had already agreed to the interview with Couric, whose show debuts tomorrow, before Seal made the comment. The interview will air Wednesday.