Jacob Elordi Looks Like He's Packing Heat as He Tans Shirtless With Olivia Jade

Here's a shirtless Jacob Elordi soaking up the sun with girlfriend Olivia Jade ... and the most interesting thing has to do with what's going on under his shorts.

The actor's got an obvious bulge in his green swim trunks ... and, frankly, it kind of looks like he's getting aroused.

Jacob's hitting an e-cigarette and boning up on Jean Cocteau's book, "The Art of Cinema" ... and there's a few more penis jokes we could make here but we're going to let you fill in the blanks.

Olivia seems to be aware of whatever is going on below Jacob's belt ... because it looks like she's trying to hold back a laugh.

Jacob and Olivia are vacationing in Italy with her famous parents ... Lori Loughlin and Mossimo Giannulli ... so we haven't seen a lot of PDA from the couple, but there's obviously some sexual tension.