Pissed off at my own mum

So ive been a single mum for abit now. I have my own place with my little man. My mum wanted to take bubs out this morning which i allowed, anyway she said shed be gone til 4 so i invited a male 'friend' round. Really hes FWB! Anyway she calls me while im having sex accusing me of having someone over which i dont understand. Like why would that be a problem if i did? Its my place and im home alone.so i make up some bs because i don't like her knowing my business. Tell her when shes heading back to mine send me a message so i can make sure im home. And then come half 3 she bangs at the door and is shouting thru the door for me to let her in so i scoot my friend out the back and let her in etc. She instantly starts checking my rooms making sure no ones there, i asked her wtf she was doing and she said oh i bet you snuck him, her, them out the back didnt you. I said it doesn't matter either way, its my life and she said she doesn't care if i had someone over she cares that i lied to her. This whole situation has just pissed me off, id get it if i lived with her but i haven't for a long time, im single i do need some action here and there i dont feel the need to broadcast it you know ?