Did biblical polygamy ever involve group sex?

Just to be clear, polygamy and group sex go against my conscience. I am a Christian, and I ask this question sincerely. Polygamy is not explicitly or unambiguously forbidden in the Bible. In fact, it is regulated (see, for example, Exodus 21:10 ), and wise patriarchs saw no problem in marrying many women (see, for example, 1 Kings 11:3 ). *First,* in the polygamy-practising society described in the Bible, if one were in a polygamous marriage, would group sex within that marriage be morally acceptable? Normally group sex involves committing the sin of fornication or adultery, but I do not see what sin it would be in a polygamous culture. *Second,* is there any biblical, historical, or cultural grounds to think that any of the polygamists in the Bible would have actually engaged in group sex, regardless of whether their society considered it morally acceptable?