Patrick Mahomes and Chiefs Friends Down Expensive Steak, Booze At Bachelor Dinner

Patrick Mahomes pulled out all the stops for his big bachelor party dinner -- eating massive, high-quality steaks and drinking 100-year-old booze in Vegas with his closest friends!!

TMZ Sports has learned ... the Super Bowl champ and his buds -- including some of his NFL teammates -- hit up Carversteak at Resorts World on Thursday ... and feasted a wagyu tomahawk rib chop with his name and Chiefs logo branded on the bone!!

We're told the guys downed Louis XIII cognac to kick off the bash ... which comes with AT LEAST a 4-figure price tag. Sheesh.

Along with the tomahawk, Mahomes and the gang chowed down on wagyu cheesesteak bites, ribeye, seared crab cakes, striploin, mac and cheese and more throughout the night ... before taking things to the Rose Rooftop for some shots of Michael Jordan's Cincoro tequila.

What's really cool?? Resorts World projected a MASSIVE picture of Pat and Brittany Matthews on its 100k-square-foot screen ... congratulating the couple on their upcoming marriage.

We're told Mahomes' Chiefs teammates Travis Kelce, Jerick McKinnon, Clyde Edwards-Helaire and Orlando Brown Jr. are in town for the fun ... so it's bound to be a great time.

As for Brittany, she's enjoying her last few days of freedom with her gal pals ... posting up with them before heading out on the town as well.