Bruce Jenner treated himself to a fresh coat for his 65th birthday.
Jenner was tooling around Malibu Tuesday when he lit up a cigarette, revealing the fire engine red nails.
It looks like he nailed up to celebrate the milestone ... his nails were unpainted earlier in the day.
What's really weird about this ... we've never seen Bruce -- a die-hard health fiend -- with a cigarette before. He's been in shape his entire adult life ... formerly known as the greatest athlete in the world.