Why won't my dog kiss me on the face?

I don't know the answer to this question but my dog has a preference of who she kissed. She will only kiss me, my sister, my brother in law, and my boyfriend.. She will not kiss my dad and he's technically the one she obeys the most. I'm not sure if that has anything to do with it but I do notice she picks and chooses the people she shows her affection too.