I'm out and always have been, but that's not true of others I've been involved with.
One time, when I was visiting an ex and her primary boyfriend, they were very clear that they are not out to all but a handful of people. The ex's daughter and their roommate were not in that handful, and that we had to be descreet. I was there for a week. During that time:
Both the roommate and daughter woke up in the morning twice to find her primary sleeping on the couch instead of me, and most likely figured out that I was in bed with her.
On one of those occasions, the daughter actually saw us in bed with out arms around each other.
She kissed me several times apparantly unaware that either the roommate or daughter could see us.
She left several clearly-visible bite marks on my neck, and I'm sure the room mate knew how they got there.
She kissed me infront of several of her friends, knowing they were watching.
Probably other things I've forgotten.
Those people had a funny idea about what "discretion" means...