Some background first. My mom (43F) has been divorced for 2-3 years, me (23M) and my brother (19 M) live with her. She has been dating a guy about her age, maybe a little older, for 2 months or so. Today my brother had a very small party with some neighbors maybe 5 people and my mom invited his lover. They had fun, got drunk and ended the party about 2AM. My brother gets upstairs to his room and he seems too drunk. I walk downstairs to get some water and I see them just cuddling and kissing in the living room, I panic and immediately go back upstairs. My mom asked me if I wanted something and I answered no. I'm a big voyeurist and I knew something might happen I go to the half of the stairs, right between the upstairs bathroom and the living room. I wait there for a while, maybe 10-15 minutes. My brother is drunk af and is going to the bathroom and back to his bedroom multiple times as he is puking constantly. I'm begging for him not to go downstairs because he will catch me and my mom will hear him coming end her sexy time. I'm waiting there until I hear some zipper action and I take a peek through the stairs, my mom is giving head to him. I tried to take some video but I guess it was too dark for the camera to capture anything. Also if she looks to the left she will undoubtedly see either me or my phone pointing at them, my legs are shaking. I then just enjoy the show and start masturbating while seeing her sucking on him, and giving him a handjob. He lifts her shirt and pulls her boobs out. At this moment my mom changed places and had much worse visibility on the stairs, so I feel a little more comfortable about watching and trying to get at least one picture. Then she decides to mount on him and here's when I decide to record all that's happening. In the audio you can hear a door opening and closing, that's my brother going to the bathroom again and again. In the end she decides to get off him, I panic once again