Obama Breaks Cardinal Presidential Rule by Donning Tiara Group of Girl Scouts convinced him to do it.

 -- Apparently only Girl Scouts can get President Obama to break one of his cardinal rules.

Chief White House photographer Pete Souza posted a photo to Instagram today showing the president donning a tiara alongside a group of Girl Scouts from Tulsa, Oklahoma. The photo, from the annual White House Science Fair, was taken in May.

Souza wrote that the girls convinced President Obama to wear the tiara for the group photo, something members of the Navy football team were unable to do in April with different headdress.

Navy presented Obama with a custom-fit helmet but he declined to try it on.

“Here’s the general rule: You don’t put stuff on your head if you’re president,” Obama said at the time. “That’s politics 101. You never look good wearing something on your head."