The 98 Degrees star was a guest on U.S. talk show Watch What Happens Live with his bandmate and brother, Drew, when he was quizzed about his relationship with the Simpson family.
Lachey, who is now married to Tv personality Vanessa Minnillo, admitted he lost touch with the singer/actress two years after their 2005 divorce, saying, "It's been years (since I've talked to Simpson). Years. Honestly, probably six years. It was like another lifetime ago."
He then took part in a question-and-answer game with host Andy Cohen and was quizzed about his ex-father-in-law, Joe Simpson, who is in the midst of a divorce from Jessica's mum Tina.
Asked what the best thing was about cutting ties with the former minister, Lachey quipped, "I don't have to play grab a** under the table on Easter Sunday!"
He quickly realised he might have landed himself in trouble after Cohen laughed and said, "That's very funny", prompting Lachey to reply, "It may not be tomorrow, but it is tonight."
Rumours about the patriarch's sexuality began surfacing last year (12) when Tina filed to end their 34-year marriage, but the Simpson family has yet to comment on the claims.