1. 'Epic banter' has just failed.
2. 'Banter' has just failed in an 'epic' way
3. A fresher tried to use every word they just learned at university in one go and ironically suffered an 'epic banter fail' themselves.
NB: NEVER say this.
Sophie: "Yeah, so much banter!"
Alison: "No, last night was a fail!"
Fresher: (panics) EPIC BANTER FAIL! *cough*