We argued again, how can I get my mom to stop talking about it?

[LouLou]

My mom didn't let me see my friend anymore so I started going behind her back and I have been sneaking around and seeing him every day after school for the last 2 months. But my mother came home early monday (I didn't know that she would be home early) and I didn't even hear her opening the front door because I was..distracted. She went up to my room and when she walked in she totally freaked out (she saw him on top of me and he had his had up my shirt, but other than that it was just some Innocent kissing) and she started screaming at us and totally embarrassed me and she called his mom and told her about it. She took my phone away and she also grounded me for a month, I don't really care about the grounding because its not a big deal but the bad thing is that she keeps bringing it up every 5 minutes. Im tiered of listening to her because she is always full of shit and even though its not a big deal because we were just making out but she just doesn't stop talking about it. I was all chills watching tv in the living room like about 20 minutes ago when she just started talking BS like "what else don't I know about?, You are too young to be doing this stuff., I cant believe you let him feel you up like that. you are so irresponsible.". I told her to leave me alone and I went to my room because im tiered of her screaming at me about this little incident because im a kid im young and stupid so I do stupid things (im 13 and he is 14) so I think that she should just let this one go and stop being such a pain. How can I get her to stop bringing it up?