Married Woman Diaries S01 E09 The Toothbrush Rhyme

Rishi & Shweta are having a good time. There's even some role play involved when suddenly Shweta's mom lands up at their door step. The episode takes a hilarious turn when Shweta's mom accuses her of having an affair outside of Marriage. There is also a hilarious toothbrush rhyme involved in it. How?