I won't give up, Rasmus, how does he treat MC who is older but usually looks younger, like a teenager or physically smaller? (I'm older and I literally look like a teenager ;,,v)
the important thing is that Rasmus doesn't really target appearance itself. he isn't the kind of person who stands there making comments about someone's body, attractiveness, weight, height, or features. most of his teasing comes from whatever situation is happening right in front of him.
so if an older MC constantly gets mistaken for younger, he'll absolutely exploit the joke when an opportunity presents itself. and he would surely find your height handy, since you can reach places in the store that others can't, especially when it comes to cleaning stuff :D