Hump Day? Donnie Wahlberg says it's "Rump Day"

If you don't follow NKOTB/Blue Bloods star Donnie Wahlberg on Twitter, you should.

Wahlberg is very self-deprecating, irreverent and funny.

Today on his Twitter account, Wahlberg decided Wednesday's should now be called "Rump Day" instead of "Hump Day." And in commemoration of "Rump Day" he began sharing various pics of his booty.

I think it's funny. And I love celebs that don't take themselves too seriously.

Of this pic Wahlberg posted "Damn, I didn't know it was that plump"

Wahlberg called this pic "Tip of Rump"
The front isn't too bad either...