Cops nabbed a couple of teenagers on the Upper West Side early yesterday morning allegedly doing what teenagers do best: Defiling a 114-year-old civil war memorial, employing a can of red spray paint to decorate antique cannonballs with happy faces, sad faces and nipples, among other things. Teenagers!

Officers patrolling the Soldiers’ and Sailors’ Memorial Monument on Riverside Drive and West 89th Street responded to a vandalism call around 3:20 a.m., where they say they found a 17-year-old boy and 15-year-old girl gleefully spray painting the monument, which was unveiled in a ceremony presided over by then-Governor Theodore Roosevelt in 1902. Poor form, kiddos.

The boy, identified as Mike Kushnir, has two prior arrests this year for fare beating, in addition to one for throwing and breaking a computer, and one for stealing from a Gristedes supermarket. He was also charged Thursday for defacing a lamp post on Riverside Drive and West 88th Street back in May, having tagged it with the word "Trap" in blue marker.

The unidentified girl has been charged as a juvenile, but also faces charges of criminal mischief and "making graffiti" for tagging a neighborhood mailbox with...her own initials. Sigh.

The number of graffiti-related arrests has risen about four percent since last year.