While I have work friends, and we do go out and drink, it's almost always within or adjacent to the context of a work event. Like maybe we're doing a co-workers happy hour. Or we had some work function that stretched into the evening, so we'll go out for dinner and drinks together afterwards. There's definitely been a few times where we were drinking for like 8hrs after a late lunch! But it's very rare for me to hang out with them outside of that. Like I can count on one hand the times I met up with co-workers on like a weekend just to head to a bar.

As far as topics, they're still friends, so we talk about all sorts of stuff. But there's definitely more of a focus on things happening at work and less about our private lives, especially spouses/SOs. My current "work best friend" will sometimes call me afterhours and we'll chat and vent about stress at work and stuff, and even some of our stresses at home/personal lives, but the latter tends to be more surface level. With my non-work friends, we'd certainly get deeper into those topics if desired.

It comes down to professionalism. That's really the "firewall" between my work friends and non-work friends. Yes my work friends and I can have fun, joke around, get a little loose when drinking, share deeper stuff about ourselves, but we never want to cross that line. Sometimes it's thin, and sometimes it's even a little blurry or dotted. But we all still strive to never (or very, very, very rarely) cross it.