Some things are best done in private, right?

I have a female friend, 'Rachel' who has a new guy the last few weeks . Of course the beginning of a new relationship is often...intense, you know? Lots of PDA, etc. This new guy has a habit that's grossing us out. He like to eat food out of Rachel's mouth. He seems to like making other people uncomfortable with it. I'm friends with Rachel and have privately said 'Hey, enoughs enough. He's into you, we get it' He still does it and she doesn't make him stop. She says it very 'intimate' and 'sensual' and she loves the attention. Fine, but not in public! is all I'm saying. 'It's no different than regular kissing' is her argument, but couples who make out all the time in front of other people make them uncomfortable too! We are good friends and hang with the same crowd it's not like I can just not invite her to things, it's more like I'll have to stay away myself. Other people around us don't like it, but don't seem as bothered as me. I can barely be around her when there's food involved (usually) knowing that as soon as she takes a bite he's going in after it! Am I being overly sensitive?