The boyfriend's mom has made a few suggestive remarks regarding him.

Recently, my boyfriend hurt his back and has been struggling to move around as he usually does. Since we’re both in our early 20s and living at home with our parents, I decided to visit him to see how he was doing. During my visit, while he was walking around, his mom jokingly said something like, “Oh, he’s showing off because you’re here!” Later, while we were all in the kitchen getting dinner, my boyfriend mentioned his back pain and how difficult it was for him to move. As I helped him carry plates, his mom made a comment like, “Well, since he can’t move, you can do whatever you want!” My boyfriend shot me a strange look, and I laughed it off, not realizing the implication. Then she added, “He might actually enjoy you being in charge, since he doesn’t have to move at all!” I finally caught on, but my initial response was a bit naive: “Wait! I was thinking that if we played tag, he wouldn’t be able to tag me back, so I’d win automatically.” That was the highlight of my week, and I’m curious—do some people just have this type of humor? I could see my friends joking this way, but given that it was about her son, it felt a bit off to me. Am I overreacting for finding it strange in the context of his mom talking about him? There were a couple of other comments, but these were the ones that made both my boyfriend and me feel awkward the most. TLDR: My boyfriend hurt his back, and his mom joked that I could "do whatever I want" to him, adding he’d probably enjoy it. Is this weird, or am I just being a prude?