Notre Dame WR Justin Brent -- No Punishment for Dating Porn Star Lisa Ann

Notre Dame may not want its players banging before marriage, but it will NOT suspend Justin Brent for "dating" porn star Lisa Ann ... TMZ Sports has learned.

A Notre Dame football spokesman says the freshman wide receiver will escape any punishment -- and will suit up for the Navy game this weekend. He added Coach Brian Kelly met with Brent when he got back to campus ... and it's no longer an issue.

It may sound strange, but sources connected with the university tell us Brent did nothing wrong. The official university stance is that students "may be subject" to punishment if they have premarital sex ... but there's no public proof Brent and the legendary "Nailin' Palin" star banged.

We're told administrators did question Brent about a leaked photo (rated PG) of him in bed with LA ... but since he had nothing to do with it getting out, there's no issue. ND officials merely warned Brent to be careful because he represents the university -- a.k.a. be smart about what you post on social media.