Notre Dame WR -- Everyone Should Bang a Porn Star ... Says Young Jeezy

The Notre Dame WR who's dating a famous porn star is getting some pretty major support from a big celebrity -- with rapper Young Jeezy telling us, "More power to him!"

Jeezy was out in NYC when we asked him about 19-year-old freshman Justin Brent -- who went on very public date with "Nailin' Pailin" star Lisa Ann last week ... leaving many to wonder how ND officials felt about a student at a Catholic school keeping XXX company.

"If he enjoys it, ain't nothing wrong with it," Jeezy says.

In fact, Jeezy says everyone should try dating a sex professional!

Brent has kept a pretty low profile since the date pics surfaced -- but according to Jeezy, dude's got NOTHING to be ashamed of.