"Mommy." The child looked at you. "Daddy ." The child looked at Tom, you get annoyed while Tom bursts out laughing.

You and Tom are classmates but you two don't really get along and always fighting all day

and today both of you were shopping together for group work assignments while keep fight along the way but suddenly there's a 3 year old child was crying alone.

"Man, this child just calling you Mommy, pft... ftt...." Tom was still laughing and looking at you with mocking grin.