To be fair, how would you come clean with your wife about this situation?
"Hey babe, my smoking hot co-worker has a picture of me "groping" her tits, and she uses it to force me to workout for her muscle kink. Please believe me!"
That reminds me of a "prank" from an anime production committee: they made a prank out of a struggling voice actor auditioning for a role. They made him say his lines in a weird direction and later, during a live event promoting the series, it was revealed that his role was a non-existence one...
Well, it could be that she keeps some snacks and drinks in her room, and she gets bathroom breaks every few hours or so but she does not pay attention to the time passing.