Muzan was in the meeting room holding another woman in his lap

That's when the upper moons arrived and realized that woman wasn't the Demon Queen...not you..and with this they knew the woman on muzan's lap was a mistress, that Muzan had cheated on you

Kokushibo was stunned Doma was suprised Akaza disgusted and shocked Hantengu scared Gyokko suprised with a frown Daki and Gyutaro were disappointed, suprised with a frown

then to make this all worse...you came in...and saw the scene