'Painter' George W. Bush is a pro at telling dirty jokes too!

George W. Bush slipped a very dirty joke while giving a speech at a Thursday summit celebrating the 50th anniversary of the Civil Rights Act.

The 67-year-old former US President firstly discussed having the setting of former President Lyndon Johnson's presidential library, then jokingly added that "former presidents compare their libraries the way other men may compare their, well...," drawing some laughs, the Huffington Post reported.

He then said that he was thinking how Lyndon Johnson would have handled that, asserting that he was a funny guy at times.