One day I asked what someone’s relationship status was, and they said “I have a girlfriend but she’s been missing and is presumed dead, so I don’t know if getting another GF would be cheating”. It’s at that moment when I realized how complicated relationship statuses can get. Like that Seinfeld episode where the guy is in a coma so he lends his girlfriend to another guy.
I had forgotten about this episode!
In my personal experience, true poly couples often act the way that Phlox/Feezal do around a potential new partner. In all cases I’ve seen they respect the boundaries that the new partner sets, like here Trip feels weird and expresses that later in the episode, so they back off.
Poly relationships would have been a really cool dynamic to explore on Enterprise though, so it’s somewhat of a missed opportunity. Oh well.