Those people sound like they are swingers. When I was on a swinger forum (before I found this awesome place) there were stories on there all the time just like this. Only, the people there werent poly so it was more jus the "ugh that guy is a pig" instead of the "I'm hurt" reaction.
"Regret for the things we did can be tempered by time; it is the regret for the things we did not do that is inconsolable." - Sydney Smith
Kyle: 27 year old male
Katie (rymmare): 25 year old female
Kids: girl: 5 years old, boy: 3 years old