I have always told my children that it's ok to cry. (Have I ever mentioned that I have all boys? And that the societal standard is "be a big boy now, don't cry!" Well I refuse to buy it.) Everybody gets hurt sometimes, and everybody has a right to cry if they need to. Or to cry if they want to. And who am I to dictate whether or not an injury (physical, emotional, or otherwise) is big enough for crying?
So I don't.
My boys all know that it's ok to cry if we need to. They also all know that sometimes we need to go to a different space (for example, to our bedroom) if our crying is loud and disturbing other people. But it is always ok to cry.
Right now my 4-year-old is in an emotionally volatile stage, and has meltdowns over being given the wrong color of cup for his milk, or if the milk was not filled to a precise height within the cup, or if someone looked at him funny, (or breathed in his general direction...). I recognize all these things as being petty little things, but if he feels that they warrant crying then I'm not going to squelch his emotions. I'd rather he let it out than learn to be emotionally constipated. However, he also knows that his outbursts are not something that the rest of us want to listen to. At present he usually decides to cry, and then hops up and runs to his room before he bursts out with the wailing. Even when I know the crying is not genuine, I am not willing to tell him that he's not allowed to feel. He'll outgrow the meltdowns, but he should never have to outgrow being able to express his feelings.
So in this house, yes, we cry.