Has anyone experienced a dog having a strange reaction to people kissing?

When I was little and my parents would kiss, my dog would run up to them, tail wagging, and try to lick their mouths.

My boyfriend and I kissed around my dog a couple years ago, and every time we did she'd turn around and sniff some random object, feigning interest in it, as though she's embarrassed to have seen.

Then my boyfriend's dog at his house would bark like crazy and growl and try to attack me.

Are these dogs strange or do other dogs react similarly?