Marc Anthony wants Jennifer Lopez to know ... she ain't the only one with a hot, young plaything -- and he's got the photos to prove it.

Anthony just went to his Facebook page and posted a photo of himself gettin' all kissy kissy with a 24-year-old Venezuelan model named Shannon de Lima.

It's the first chick Marc has been romantically linked with since he split with J.Lo back in July.

Of course, 42-year-old Lopez rebounded with 24-year-old backup dancer Casper Smart.