This article is from the Polyamory FAQ, by firstname.lastname@example.org (H. Wilper) with numerous contributions by others.
As Martin Schafer says:
"If you don't think you are doing anything wrong, and can
honestly explain that, they'll probably think it's pretty
neat. For some of us having more people involved in child
rearing is a big practical benefit of our lifestyle. The
details of how this works is a fertile topic for discussion,
both here and among the individuals involved."