But a mature 16. 
Ok - yea what @momofboiler1 says. No phone. Lights out.
College or life is upcoming and you don’t want to blow it.
And there will be drama - such as choosing the wrong school for her or if they are broken up, she’s got a prom date…I don’t.
I went ahead and added his age to your initial post to avoid further confusion
My advice is condoms. Not being snarky, but they are smitten and better safe than sorry.
You mention, “she is mostly polite” - that is interesting phrasing - or maybe I’m reading into it - does she act appropriate around your family?
I think similar rules as you would have with his friends. Same curfew. Offer to host some friends at your house including girlfriend. Make some occasions where they can be together but have other friends around
Yes, this! Besides pregnancy (which is already a big enough reason), the risks that go along with unprotected sex are simply not worth it. Every young man and woman needs to have condoms easily and readily available, and no judgment.
Are you able to speak directly to them about this? Not confrontationally, but like “we’re all trying to do our best raising our kids while maintaining a good relationship with them. This is a house rule we have found important for the functioning of our family and it would be a big help if you supported us by not inviting him to do things on school nights.” (From what you’ve said, maybe you’ve already specifically addressed it like this though… 
I’m probably the outlier here but I’d probably sit down and have a conversation with my son if, at 16, he was spending all his free time with a girlfriend. Much like your initial post here, you make it clear you like her but feel he should also maintain his friendships by doing social things with them. I think maintaining independence and growing friendships is important at all stages of life, some may disagree.
Totally agree on the condoms, we’ve had many discussions.
So the “mostly polite” is that she is polite to us and has nice manners at our home. But, she tells our son that we are unfair about no going out on weeknights and turning his phone in at night. He was never an argumentative kid until she showed up.
I haven’t directly addressed it with them. I believe they know. But you’re right and the next time we will probably need to.
She’s a heathen…hope they break up
No - this is what kids do - they know right - until they get old and realize, maybe my parents weren’t wrong.
But yes, not good to diss the inlaws.
Accidentally replied to the wrong poster.
That’s it exactly. At least how it seems to us.
No idea what to tell you to do or how to fix this tricky situation.
What I do know is that I absolutely cannot stand parents who undercut other parents’ relationships with their own child. The disingenuous “oh we’re just so cool and chill and are happy to encourage an all consuming relationship with my kid and yours, because you guys are all uptight and your kid likes us better, so we win!”
It’s really obvious to any observers and it’s frickin’ loathsome.
But… he’s 16 and spreading his wings (in typical selfish-teen fashion). It’s possible he would have been argumentative with or without the GF. Of course there are now lots more potential topics / rules to debate.
Absolutely. You’re right.
100%!!! I have been there even with platonic “BFF” relationships. And I can tell you from hard experience that the type of parents who do this will also be the first ones to turn a megaton of “middle school mean girl” energy on your kid when the day comes that there’s any sort of conflict or distancing between the young people. Be careful, and hold the boundaries that they are not.
Stick with the household rules unashamedly and have a talk with him about dissing his other friends.
Story: my D started dating her husband at 16. He had a long term best friend, almost an extra brother best friend. He’d third wheel them all the time and it drove her nuts. He was jealous. Later, when he was a best man at their wedding he gave a very sweet speech about how jealous he had been and how he thought she was great now. He’s still around all the time and she doesn’t mind any more. It’s wonderful. Like family to her now too.
I also met my husband at 16. I don’t regret our relationship at all, we’ve been happily married for over 30 years, but I do regret how much we spent time with only each other and didn’t maintain other friendships in those dating years. We definitely encouraged our D to not do that. She and the future spouse actually went to different distant colleges and long distance dated for four (long!) years. D’s husband’s parents also met at 16, and we have another couple in our circle that met at 16. Not so uncommon. There’s no one formula for successful relationships.
Your initial post and this is so familiar to me. Unfortunately I have no good advice except keep the lines of communication open with your son and let him know you are always there for him. My son and I had been pretty close before he started dating her when he was 16 and she was 15. I went through a lot of heartache in part because I was hurt. (I also have 2 other sons and did not have similar issues with them and their girlfriends.) He didn’t want to spend time with our family because her house was better - her family was wealthier and more permissive. She also had a lot of family issues but relied on him to get her through them. Fortunately his grades were fine and he maintained the minimum for his sport and other activities. In retrospect I regret a lot of our arguments about it - they made me feel miserable - but at the time I didn’t see it from the eventual perspective. They broke up after 5 years when she abruptly started dating someone else, he was devastated and took a while to recover. But, we now have repaired our relationship for the most part and I think he recognizes what he gave up including time with us and his siblings (who are closer to each other now because they spent more time doing family things). I don’t know how you make a teenager have that perspective though. Just love them through it.
Thank you so much for your post, it certainly feels like the same sort of situation. Just had to shoot down another going out on a school night request today. I’m getting close to reaching out to the girlfriend’s family and discussing our rules. I’m wary of it becoming an us vs them thing though.
My husband and I were also discussing sending him on some kind of summer program, either an Outward Bound kind of thing or maybe overseas for his foreign language just to give him some separation next summer, even if they break up before that it could be good for him.
So what are these going out on a school night requests? Dinner? Hanging out? Actually going out? My kids always had so many activities afterschool this wasn’t really a thing - than covid hit and everything changed. I’m just finding it odd that the other parents have so many weekday events they’re inviting him to.
He actually only has Wednesday nights free! That’s what’s so crazy. Tonight he and his girlfriend wanted to go into the city to go to an event at a music store. We don’t let him hang out in the city at night period, even on weekends, unless it’s for a concert, sports game, or something really specific. We live near Portland, it’s not awesome right now in many areas.
I’m not blaming the parents for this one, I’m surprised they would let their daughter go though, most of our friends don’t allow their kids into Portland at all, except for special events.