I was at my assembly when this was discussed last week. Of course I hadn't prepared and I heard "no rules about limits", or at least I thought I did.
Here's the direct quote from the Watchtower study article.
"Although the Bible does not provide specific rules about the kinds and limits of love play that might be associated with natural sexual intimacy, it mentions displays of affection."
THE WATCHTOWER (STUDY EDITION) AUGUST 2016 : Making Christian Marriage a Success, paragraph 8.
What say you?