Mötley Crüe's appearance at this year's Rock in Rio festival likely marked the last-ever time they'll ever share a stage with Metallica, and Crüe drummer Tommy Lee couldn't resist the opportunity to take a jab at his old nemesis Lars Ulrich.

Shortly after the bands wrapped up their festival commitments, Lee took to Twitter to insult Ulrich with a meme generator created to promote the N.W.A biopic Straight Outta Compton. The generator allows users to insert a photo and a word indicating what the user's "straight outta" — and Lee used it to goof on Ulrich's oft-criticized drumming ability:

As most fans are likely aware, the animosity between the bands goes back for decades. In one documentary interview, Ulrich boasted of heckling Nikki Sixx outside a club in 1982 (and being able to easily outrun him, thanks to the Crüe bassist's tall platform stage boots); years later, he publicly insulted the entire band, accusing them of performing to tape at the 1997 American Music Awards.

Ulrich's criticism rankled Sixx, who used an AOL forum to respond with a scathing note — addressed to "Dear, Sweet, Fat, Balding, Larz" — that retorted, "Taking your ever-moronic soapbox position on a subject that's NONE of your f---ing business has made you out to be an a--hole as usual. Considering that me and Tommy know that your live tapes have been re-recorded. And ALL your instruments were repaired in Pro Tools (and had that balls to lie to your fans an call it a 'live' album) ... People in glass houses should NOT throw rocks!! Considering your bulls--- to the press, we feel it's only fair to return the punch!! ...Your [sic] such a poseur ... Thanks for releasing that 'load' of s--- CD of yours ... you made more room for us!"

Things have cooled off between the bands in recent years — Ulrich has guested on Sixx's Sixx Sense radio show — and given Ulrich's evident ability to take insults in stride, it seems unlikely that something as silly as a meme will start a new feud. On the other hand, if anyone from Metallica wants to respond in kind, the "Straight Outta Somewhere" meme generator is still active.

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