When you are the toll and want to carry the smoll, but the smoll is a cyborg and carrying his weight is like trying to carry a baby elephant on your back.
I like to headcanon that Genji is actually sort of heavy due to all the cybernetics and is also a lot stronger than people think. Reaper can’t carry the smoll but Genji just carries him around like a princess without any trouble.
His pride is wounded
but he secretly likes being carried like a princess in Genji’s smoll yet strong arms.