I find this question a little odd. You've just met them and you are upset because of the amount of affection that they show each other. What about it bothers you? It doesn't sound sexual or anything (which would be another matter)--- it sounds like a mother and daughter that are very close and show it through kisses. What's the big deal?
Maybe it would be worth examining why it bothers you so much.
What is your relationship to them , also what culture are they as sometimes this determines the affection level, personally I dont see any harm in the affection, some families are demonstrative ,small children like to fondle their Moms , I have seen many instances in the US where children still like to touch their Moms breast , remembering the breast feeding, I have never interpreted it as anything other than affection, indeed any unusual behavior that could be bad is more surruptious,this is too open for it to be interpreted otherwise.