Caught brother touching himself

So about a year ago i caught my brother masturbating. I screamed "ew" closed my eyes and walked back to my room. He apologized. And we Never mentioned anything after that. Yesterday my bf and i got home and we walked to my room. My brothers room is next to mine. Our rooms are by the kitchen. Anyway i go to the kitchen to wash my hands and i can see into his room from where im standing wnd i see his hand moving up and down but hes watching tv is was just like "wtf is he really doing that with the door open" i felt so embarrassed that maybe my bf saw. I didnt see his penis. It was dark in the kitchen and in his room but his tv lit his room. Its so gross and awkward!!! Ugh.