How do I tell my mom we got back together

so background story me and this guy talked last summer for almost 3 months and I guess i got my hopes up that we would be in a relationship but when he said he wasn’t ready it really broke my heart and because of this my mom doesn’t like him but fast forward to now we’ve been talking (behind my moms back) and we both agreed that we want to be together the only thing stopping us is my mom he wants me to tell her so that he can officially ask me out but I know my mom is gonna react badly and i’m scared she’s already told me that i’m not even allowed to have him as a friend but he makes me happy and i feel safe with him and whenever we’re together it’s like it’s just me and him and all our problems just don’t exist my mom has always been very controlling and i do everything to make her happy and i know telling her about him will end badly just the idea of approaching the subject scares me he’s a really good guy and i like him a lot and i don’t want to stop seeing him because of my mom what should I do?