Celebrity News:

Britney Spears completed her first co-parenting class with Kevin Federline -- and left the Beverly Hills Hotel completely tanked up -- with gas!

TMZ caught the attentive valet at the ritzy hotel, filling up Britney's gas tank as she met with a counselor inside. Sources tell us she also paid to get her Mercedes washed as well.

The price of the gas isn't cheap -- a whole $4.50 a gallon, yikes! That's more than a buck higher than the highest grade gas in L.A. -- but at least it saves her from making yet another paparazzi-filled pit stop later on!