I have. Tried to do the poly thing a few times, but the folks involved were far too emotionally messy for a serious relationship.
That would probably be the way I'd want to go, but, personally, I've seen very very very very few poly relationships with a good dynamic between partners, remained chill, and were emotionally healthy.
Big ol' box of tasty protein bars save me when this happens! I keep them around for when this inevitably happens.. which is often.