line is drawn at:

1. involving ppl who don't consent. which is why some are against polygamy b/c it's too common for women and girls to be coerced into those polygamous marriages. IMO as long as everyone involved is consenting to the arrangement i have no problem w/polygamy. and i'd have no problem w/any state issuing a license to a couple who wants to engage in polygamy. or polyandry, of course.

2. no kids. b/c kids cannot offer consent.

3. no animals. b/c animals are not ppl. and they cannot consent.

4. no inanimate objects. b/c they are not ppl.