Austin Butler and Kaia Gerber Lounge Poolside During Mexican Vacation

Austin Butler's 'Elvis' movie went 0 for 8 at the Oscars -- and while it's unclear if the King himself is feeling down, we do know things have gone south (of the border) for him.

The actor was hanging in Cabo San Lucas with his GF, Kaia Gerber, last week -- photographed lounging poolside at their fancy hotel. They were in swimwear -- both looking smoking hot, no doubt -- but there doesn't seem to be too much heartbreak.

AB and Kaia looked fairly neutral as they took in the sunshine ... with just a little bit of PDA.

After a bit of R&R, Austin and Kaia hopped on a golf cart and rolled on over to another part of the resort ... paps snapped the model leaning her head on her boo thang's shoulder as he handled steering duties.

While we're sure Austin/Kaia are enjoying themselves, ya gotta imagine the guy is somewhat bummed about getting iced out of any statuette glory for the most important award show of his life. He had a lot of buzz and momentum behind him ... but so did Brendan Fraser.

Of course, the latter ended up taking home gold for his role in 'The Whale' ... and as we all saw, 'EEAAO,' swept just about everything else -- clearing the deck on all the big categories.