Hey there, km34... I have no doubt that you have been respectful for years, along with your husband. If you're posting on a polyamory forum, chances are you have the tools necessarily emotionally, coversationally, and experience-wise to handle (and work within) situations that some 40+ year olds cannot. Are you unique to your age bracket? Maybe, Maybe not. It really does boil down to experience, doesn't it? You mention that you have a good amount of life experience, and that goes a long way.
In regards to the guy I've been talking about, he's grown up in a small town, still lives with his parents, and this is his first time in engaging (more than once) with someone who happens to be partnered. I'd wager to say his experience is lesser than yours (in this realm), and this is why he's acting out in different ways, and is probably processing our meeting on his own, as well, currently. I do know where you're coming from, and felt the same way when 30+, 40+ year olds would have an opinion based solely on my age (when I was in my early twenties), and it angered me so much that I would try to make a point whenever I could to make my life experience be heard, fighting against an unwarranted judgment call.
Remembering that, and looking at my situation specifically, age isn't as much a factor, as much as it is
life experience, of course. I had said that if the guy handled it maturely "(and without digs, jabs, a competitive nature and demonstrated a jealousy streak in our first meeting about my and my partners relationship) there wouldn't be an issue, and I would've considered him a full-blown adult, not just legally."
I do hope he unlearns 'social norms (like trying to tell people to BACK OFF, HE'S MINE without actually saying it)', as it seems that he's here to stay for a while... or at least my partner is now staking his
claim (per our conversation last night), and basically had tried to discredit all of my observations, chalking it up to 'he's just kidding!', and 'I think he was being discreet'.
I like your approach...it's a reminder that here's an opportunity for allowing someone to grow. I'm not too enthused because my emotions are involved, and this first impression was a doozy for me, but we do teach others how to treat us.
Thanks for your wisdom in this... I'm relatively new at this type of thing (as you might've read), and I appreciate your viewpoint.