My mum walked in on me and my boyfriend getting freaky

Okay so I listen to a lot of Reddit videos and after this situation neither me nor my boyfriend know what to do so any advice is welcome.

Background information that might be helpful: My mum raised me as a single parent, we have always been close and it’s always been me and her. Me and my boyfriend have been together for two and a half years. I’m sorry if the spelling and grammar is bad I’m drunk while writing this and this just happened. Both me and him live at home and split our time between both our homes.

Me and my boyfriend (both 18) went out with my best friend and her boyfriend (F+M19) for Valentine’s Day. It was last minute and we just decided to go out. We had a really good time, had a few too many drinks and when my friend and her boyfriend decided to go home me and my boyfriend got a taxi home. We got back to my house and thing started to heat up. Once in my room we started going through the motions of foreplay when my mother (F37) walks into my bedroom and audibly gasps. Neither of us were naked but my boyfriend had started to take my pants off and he was just in underwear. She shuts the door and I quickly rushed out (putting my pants back on) to talk to her and she just perfusly apologised and said she was going back to bed and she thought something had fallen over in my room but promised never to open the door again. In the two and a half years me and my boyfriend have been together we have never been caught close to doing the deed and neither of us really know how to go about handleing this now. My boyfriend is worried my mum is going to think badly of him but I don’t as we are both adults, she knows we have sex. I do know the best cause of action is probably to speak to my mum? I’m not really sure and I wouldn’t know what to say. My boyfriend is worried this will damage his relationship with my mum and consdering they have gotten on really well he doesn’t know what to do. Can anybody offer any advice on how I talk to my mum? Or do I just pretend it didn’t happen? How can we even have sex now while we both still live at home with parents? Might seem shallow but we are a really active couple and I don’t want this to affect our sex life whej we are at my house.