I had a teacher who taught a class that regularly featured his vacation photos because he spent his summers traveling. Sounds super corny, but he managed to make it interesting, and the first-person account brought to life the countries, religions and philosophies that we learning about. His wife occasionally showed up in those pictures.

My school also had two married teachers who shared a surname. We all knew they were married.

There were also a few teachers (band, orchestra, sports coaches) whose spouses would volunteer at events and travel with them.

Also quite a few teachers wore religious symbols -- cross on a necklace kind of thing. And quite a few of my teachers had pictures of their families on their desks. They didn't make a big deal about it, but evidence was in plain sight.

Now, I was in the high school in the 90s. I'm not sure when you think this changed.