There are countries where it is customary to kiss on cheek while greeting or saying goodbye, as a display of friendship and affection. There are countries where it’s not. The problem is, when you travel you never know where it’s OK and how many kisses are required. As this article points out, the number of kisses can range from one to four, also depending on the gender of the person you’re greeting. Same as in France, Italy has a different behavior depending on the region, with more kisses in the South. To make it more interesting, I’ve found that in Europe you kiss the right cheek first, while in Brazil it’s the other way around. In my trips to Rio I’ve made cheek kissing mistakes several times.