Supposed to be pilot slang. If you vomit into your mask, you'd better suck it up. Otherwise, you can inhale it and die.
Evil: why are you crying?
Girl: My life is falling apart, my boyfriend dumped me, my grades are falling and my parents hate me.
Evil: Stop being emo and suck it up, jeesh, you're depressing me.
Girl: (sniffle) sorry....