public displays of affection

I remembered when I first went to Melbourne. I did not experience culture shock but I did gawk when i saw couples locking lips in public. i was 25 at that time. so sakai hor....in malaysia, close proximity is prohibited to the point where you get fined or hauled to court. so what is acceptable?

• holding hands
• holding hips (that's difficult for me, cos I've got a huge ass, didnt work for my former beau, but we fit together nicely - for my current dear)
  
• peck on cheek (now we define peck as less than 2 seconds contact..haha)
• peck on lips

what's wrong with public displays of affection? afraid that it would lead to something more? what a backward way of thinking..we're teaching our children that love is wrong, it should be hidden behind closed doors. that's like banning cars because accidents kill