And men can be condescending to men. Many engineers have a tendency to over-rate how much we know and to under-rate how much the other person knows, and it can come out in lots of ways in lots of interactions. It's not good in any of them.

And the time I did "mansplaining" the worst, I didn't do it because the recipient was female. I did it because she was a manager. I assumed she was only a manager. Big mistake - she wasn't. (Even if she had been only a manager, I still shouldn't have treated her like she didn't know what she was talking about, though.)