I happened to show up on a Wednesday with all my k...

I happened to show up on a Wednesday with all my kids. We visited the tar pits first then worked our way over toward LACMA. We've never been here before. We saw the signs that said the museum was closed on Wednesday's but it also said the courtyard and large exhibits are open daily.
They were setting up for an event in the court yard. There's several buildings so I asked someone which one was LACMA. The guy pointed to the building behind him and mentioned they're closed but told us we could enter the building in front of him to use the restroom.
Again, we have never been here. As soon as we walk in the building the security tried to tell us we couldn't be there. We said we were looking for the restroom. She then started telling each of my kids not to touch the open exhibit that looks like a part of the structure. When we were leaving we thought we could exit through the back door. All six of us walked right past the security up the stairs toward the next courtyard. Again, we got confronted by another security. They got more and more rude. This lady stops us abruptly and angrily tells us they're closed. I look around and notice there are well dressed couples walking around freely and didn't see anyone approach them ever.
We walk back down the stairs and the security we passed on the way up said, "I told you we're closed". I told her we thought we could get out that way. Then she asked, " Why did you take the elevator? I would have told you that's not an exit." Was I supposed to play along with her story?
I felt very unwelcome and discriminated. We weren't even trying to be there. We definitely won't come back! There are plenty of other museums that welcome families.