Jim Harbaugh burns Ohio State's AD by reminding him of that whole 'tattoo fiasco'

Things have become testy between Jim Harbaugh and Ohio State.

On Tuesday, Buckeyes athletic director Gene Smith fired a shot across the bow at Harbaugh over the Michigan head coach's controversial spring practice and pseudo-recruiting tour at the IMG Academy in Florida:

Ohio State AD Gene Smith on holding spring practice in Florida: "If we were jump starting our program, I'd probably try to do that too."

— Ben Axelrod (@BenAxelrod) March 22, 2016

On Tuesday night, Harbaugh shot back with force on Twitter:

Good to see Director Smith being relevant again after the tattoo fiasco. Welcome back!

— Coach Harbaugh (@CoachJim4UM) March 23, 2016

Yes, Harbaugh went there.

Smith was in charge at Ohio State during the Buckeyes' institutional scandal that unfolded in 2011. That's when head coach Jim Tressel was fired and the university faced a 2012 bowl ban over players exchanging memorabilia and autographs for free and cut-rate tattoos, in violation of NCAA rules.

Tressel lost his job, and Smith's athletic department found itself punished for not being forthright about it. The whole ordeal turned into a massive embarrassment for Smith and Ohio State, and it may well have cost the Buckeyes a national title.

The gloves are completely off at this point, and we're approaching a bench-clearing brawl. Former Ohio State running back Ezekiel Elliott has hopped into the fray, too.

@CoachJim4UM Welcome to the big house coach. Better luck next time pic.twitter.com/TKrXfEthH8

— EzekielElliott#⃣1⃣5⃣ (@EzekielElliott) March 23, 2016

Did Harbaugh bring a garden hose to a squirt gun fight? Perhaps. Is this fun? Absolutely.