bottles for her uncles. Her and all her cousins, similar ages, would sneak a sip nearly every time. It was irresponsible. She's fine. All her cousins are fine. She's very close with her entire family and everyone, uncles, cousins, still see each other on almost a weekly basis. They take care of each other and celebrate one another. It's a great family that I'm sure most people would be envious to be part of. They did it to spend time together and they spent a lot of time together.

There are two big issues I see with your situation. #1 your son is not related to this person and you weren't invited to see what was going on, and on top of that I imagine he already assumed you wouldn't approve. #2 this guy isn't drinking to increase a family bond, relax and spend time with those he loves. This guy is drinking to play video games, an activity that to me shuts those around you out. This type of drinking seems pretty selfish in nature, pretty immature, and pretty petty, like he just does it to be a rebel.

I would confront him directly about it. I would let him know what drinking is for, to spend time together and build bonds, and that him drinking around little kids while he plays video games is something a real jack donkey who needs to grow up would do.

Tell him next time to shut off the video games, invite the kids parents (you) over and you'll happily refill his beer mug for him and you can sit and chat about what being a father and friend is all about.