Wtf do I do

It's a long read!

I am stuck in the middle of my sister and my boyfriend!

They both hate each other I honestly dont know why they have never gotten along(I think its because there so alike)

Me and my boyfriend have been together for four years and we have lived with my parents( due to his family kicking him out no fault if his own it's just his mothers a bitch😂)

Last year my sister moved back home because her and her boyfriend spilt up no big deal I missed her. Never got to see her when she was with him. All was good for a few months no arguments from either of them.

Then all of a sudden everything the other did pissed the other off like honestly EVERYTHING!

We have pretty thin walls in the house so we can hear alot, my boyfriend goes to bed early because he starts work early af in the morning, and my sister plays on her xbox in her room she has her headset on and I have to say she shouts she doesnt know shes been so loud but she is.... so she wakes him up because of her loud talking and he gets SO ANGRY he HATES been woken up especially when he has a few hours before he needs to get up for work, he tells her pretty rudely to shut up, ovs her having the headset on she doesnt hear, she he LEGIT SHOUTS SHUT THE FUCK UP as he is punching the pillow and the bed( he gets angry af sometimes) and she dint listen so I messaged her to tell her to be a bit more quieter(nice as possible) just because he would take it out on me if she dint listen, so again she dint listen and spoke louder so he had enough went down stairs and turn there wifi off( we have separate wifis) and ofc she gets angry af was messaging me about how it's either her or him.he falls asleep as it's quite now but barley every moment I make seems to annoy tf outta him. I'm trying my best to be quite so he doesnt flip on me which he does alot(as I said anger issues) but my sister have anger issues too! They push each others buttons all the time!

I should say my sister is 29 and my boyfriend is 26 SHE THEY ARE BOTH ADULTS

but they act like kids

Serisouly wft do I do I'm clueless iv trued sitting them down and talking it out it doesnt work

Any advice on this?