Both are absolutely acceptable, the second is more colloquial.

I was enjoying a gelato in Prague when[*] a young German guy came up and asked me about the grammaticality of his t-shirt. One of his classmates had designed it and it featured a shark leaping from a manhole with the legend "Shit! Outsite!" I gave some rambling response because at first I read "Outsite!" as an attempt at "Out of sight!" rather than "Outside!"


[*] I need to be able to start more sentences this way.