Seriously? OMG! WTF?

Derek Hough/Facebook

On Saturday, Derek Hough turned the big 4-0! However, you would not know it by looking at the Dancing with the Stars judge!

And he knows that too. As he explained, “For the past 5 years, I’ve been looking in the bathroom mirror and telling @hayley.erbert, ‘Not bad for 40!’

“She’d always laugh and remind me, ‘You’re not 40 yet, you can’t say that.’
“Well, today’s the day I can officially say it:
“Hey, not bad for 40”

Not bad for 40 at all!