Kiefer Sutherland -- Boozes With Canucks ... Flashes Nipples

Kiefer Sutherland + a bottle of Scotch + Canadian love = DRUNKEN STRIP SHOW!

It all went down in Calgary this weekend when Kiefer and Demi Moore -- who are in town shooting a movie together -- hit up a bar called Bear & Kilt Freehouse for some libations.

Our bar sources tell us ... Demi eventually left, but Kiefer kept the party going ... drinking with his pal Brad Mirman (the screenwriter on the film) and local fans. From the pics, taken inside the bar, it's clear Kiefer let loose.

The owner of the bar tells us ... Kiefer definitely had a lot of fun, and spent the night drinking his signature booze, J&B Scotch, which the bar was told to have on hand before KS arrived.

And just in case you don't believe that J&B really is Kiefer's favorite, here he is a few years ago ... dressed as a giant J&B bottle.