Man up, Dude.

Is it wrong to say to a whinny almost three year old, "Man up dude"?

Here is the context. I was changing his diaper and his "blankey" was downstairs where he left it. The whole time I changed him he whined about needing his blankey. I told him we'd have it in two minutes just as soon as he had a clean diaper, but no. He kept whining, in a really sweet but needy almost 3 year old sort of way, but still annoying. As we walked downstairs, I said, "We're going to get your blankey now. So stop whining. Man up, Dude." This of course made me snicker, which made him ask,

"What's funny Daddy?"

"I'm just wondering if it's okay to tell an almost 3 year old to man up, Dude."

"Oh." He said and snickered with me. So, I guess it's ok.

Thoughts anyone?