Bros Before Hos

Jesse McCartney boozes it up this past weekend with his boys!

Now, the Leaving singer is 21 – so that’s legal and all.

But, that one boys in the middle of the mandwich looks like MTV star and skateboard pro Ryan Sheckler, 18 years-old and not of legal drinking age in America.

Naughty naughty!

P.S. Chug it, Jesse! Chug it!