Meaning of “show sb up” - Learner’s Dictionary

show sb up

phrasal verb with show us uk /ʃəʊ/ verb past tense showed, past participle shown

to behave in a way that makes someone you are with feel embarrassed:

I didn't want my parents there, showing me up in front of all my friends.

(Definition of “show sb up” from the Cambridge Learner’s Dictionary © Cambridge University Press)