Ryan Seacrest Junk-Grabbing ... Wine-Guzzling Fun!

7/2/2015 8:40 AM PDT

Thisssss ... is Ryan Seacrest acting like a raging frat boy on Spring Break -- with his buddy, Thor -- and it's kinda awesome.

It's a side of Seacrest we never get to see -- but while partying with Chris Hemsworth on a yacht off the coast of Italy, he let loose ... swigging wine from a bottle and grabbing his crotch with reckless abandon.

Funniest part of Ryan's version of going HAM -- the bottle he's chugging looks a lot like ... rosé! Yeah, it's probably a $1,000 bottle, but still ... rosé?

Baby steps.