I would like to know if there is a name for the fallacy used in the following conversation. [The content is arbitrarily chosen]
A: Men have to deal with sexism in dating.
B: That is nothing compared to the sexism women face in marriages.
So, here the topic of interest is "sexism against men", and not a comparative study of sexism faced by various genders. However, person B tries to nullify the suffering of one group of people, by introducing a scale of suffering.
A: I had to sleep on the street that night.
B: That is nothing compared to what the homeless people deal with on a daily basis.
What is the name for this fallacy?