M>А threesomes/grouppensex вполне законен.
Секс — да. А совместное проживание — это уже полигамия, преступление.

Most states base their polygamy laws on the MODEL PENAL CODE section 230.1, which provides that a person is guilty of the third-degree felony of polygamy if he or she marries or cohabits with more than one spouse at a time in purported exercise of the right of plural marriage.

Read more: Polygamy — The Crime — Marriage, Law, Person, Cohabitation, Spouse, and Valid http://law.jrank.org/pages/9272/Polygamy-Crime.html#ixzz1TJYsJCMi

http://law.jrank.org/pages/9272/Polygamy-Crime.html