Allspeak Danny + Dc
Danny has acquired Omnilingualism/All-Tongue/Allspeak. He could speak any language fluently, which helped him in school, even if he changed languages while speaking a few times.
Mr Lancer cried in joy as Danny spoke fluently in Latin, French and Spanish.
So, while attending a space convention, he overheard a girl complaining about it to her sister about how awful the event was.
His desire to listen to what the Guide had to say was so strong that he couldn't stop himself and asked them to be quiet.
It didn't occur to Danny that he spoke Kryptonian to the girls. The mother language of the girls, who were the super heroines Supergirl and Powergirl.
Danny then listened and followed the tour guide, ignoring the two girls completely. Who were totally shocked.
He then used his powers and was gone after the convention closed.
Leaving behind Supergirl and Powergirl, who really wanted to talk to him.