my bf/ mother?

so me and my bf where talking on the phone and i told him about my mom and how much i hated that she was heartbroken and he randomly said "oh if she was single i would date your mom" i was like wtf after that i didn't how to react so I acted so weird because i don't know 🤷🏻‍♀️ what to do next I know this isn't right i felt like i don't know so confused any advice on what i should do next? he says he's sorry and that he didn't meant that but idk how to respond this is my second boyfriend and idk much about relationships help!!!!!