haha did Italians not understand english?

A girl gets thrown up on. She's horrified. Her bf shows up on a motorcycle.

"what happened?"

"he THREW UP ON ME!!!!"

Bf says something i couldn't quite make out, sounded weirdly like, "oh rad, a new fad".

Girl says, "oh i knew you'd understand!" and happily gets on the bike so they can ride off together.

What in the hell!??! Who wrote this? Why would they write this? Did they not understand that this makes absolutely zero sense in english? Was something lost in translation or is this director just intentionally making something as absurd and goofy as possible?