Mark Wahlberg Wearing Short Shorts in Barbados

Mark Wahlberg is flirting with Speedo territory with his latest swimwear choice down in the Caribbean ... because he's wearing some seriously short shorts.

Check out this photo of Marky Mark strutting his stuff down the beach on the west side of Barbados on Tuesday ... he's rocking a pair of baby-blue shorts that are riding way up his thighs.

Mark is showing lots of leg here, and it looks like he doesn't skip leg day ... because the dude is absolutely jacked.

Photogs have been snapping lots of pics of Mark as he enjoys a tropical getaway with his wife Rhea Durham ... and with each passing day, it looks like his bottoms get shorter and shorter.

Maybe Mark is waiting for the new year to bust out that Speedo ... and you know the paps will be all over it if he does.