Because of their stupid rules you actually go as far as you can while you have the opportunity, I probably would have waited longer to be with my BF when I was a JW but we found ourselves alone for the first time - in between chaperones and we went for it.
Their ridiculousness can really back you into a corner.
I feel sorry for the people that have to constantly chaperone - usually the spinsters they think have nothing better to do get asked. They feel obligated to 'do the right thing' and probably also hope to get an invite to the wedding, not much else to celebrate in that religion.