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"I heard you're doing the Super Bowl, so I wanted to help you out," Smith says in an Instagram video.

Will Smith just joined Instagram, and his good pal Justin Timberlake greeted him with a sarcastic welcome via a #ThrowbackThursday post.

But it's Smith's savage response that's got the internet talking.

"JT -- thanks a lot for the post and the brief education about Instagram, man," Smith said in a video he shared on the platform Friday. "This is my first day, so I'm appreciating the hookup, but, man, I know what #ThrowbackThursday is. I ain't been in a hole."

"I heard you're doing the Super Bowl, so I wanted to help you out. The things to avoid at the Super Bowl is like -- just avoid that," Smith added, lifting his shift and flashing his nipple.

And in case you've been in a hole, the friendly troll was in reference to the 2004 Super Bowl halftime show, where Timberlake ripped off Janet Jackson's top, exposing her pierced nipple on stage.

Timberlake's initial post was a photo of he and Smith at the 2013 MTV Video Music Awards, which he captioned, "Welcome to Instagram, Will Smith. This is called a #TBT. Which means Throwback Thursday. Which is a photo you post on Thursdays that you like, that was taken in the past. I like this photo because it's a photo of you and me. And we look like we are having a serious conversation about something very important. And that makes me feel important."

See Smith's full video and Timberlake's initial post below.

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