What is the most (emotionally) touching thing you have seen a couple do in public.

Always the worst with you people. What is the nastiest/most disgusting/most horrifying/ piece of x that you have ever seen?

Let's try something a touch more positive. What is the most emotionally touching thing you have ever seen a couple do? Hold hands, buy something, could be anything so long as it isn't just round peg in the round hole action.