Does my bfs mom not like me?

I don’t know if I’m overthinking this or not.
My boyfriend’s mom is generally nice, but she’s made a couple of comments that made me feel like an inconvenience. Once she came up to my boyfriend, kept looking at me, and repeatedly said, “You didn’t tell us she was coming over. We didn’t know she was coming over.” I completely understand wanting a heads-up before having guests over, but the way she kept emphasizing that while looking at me made me feel really uncomfortable.

More recently, my boyfriend asked if she could leave the house a little earlier so we could have some privacy, even though she was already planning on leaving early anyway. She looked at me, laughed, and said, “I don’t want to say it’s because of you,but it is.”
The thing is, he was the one who asked, not me. He didn’t say anything after she said it—he just stayed silent—which honestly made me feel even worse. I left feeling like I was being blamed for something I didn’t even ask for.

Am I reading too much into this, or would you also take that as a backhanded comment?