The desk sargent is too tight lipped.

Hint 1 of 5:

Maybe he'd open his lips for something other than a question.

Hint 2 of 5:

He looks a bit hungry to me.

Hint 3 of 5:

Did you see the samwich vendor yet?

Hint 4 of 5:

Did you get the coupon from the bum's paper yet?

Hint 5 of 5:

Give samwich coupon to Luigi, and give the food to sarg.