Forcing my boyfriend to watch me have sex with his cousin [girlfriend’s perspective]

Me F47 and my boyfriend M28 have a competitive streak mostly regarding emotionally breaking each other.
He has a cousin M26 who my bf hates. Not a bully but someone he hate because they get compared even in their families to each other academically and carrer wise. They both hate and have reasons to be jealous of each other. So I decided to talk to him and said if we could have sex in front of my boyfriend and invited him over on Saturday.
When he said he's nearby I asked my boyfriend to help with a cuff I "accidentally" locked on a railing type of thing on my fireplace. When my bf was trying to help I had him cuffed and stuck. When I heard the door bell I dropped my robe, walked to the door naked and welcomed his cousin inside. As soon as he saw him my boyfriend went, baby please don't. Not him. Come on. Why him. And more and more complaints with a broken voice which I loved. His cousin manhandled and used me like a complete slut for like 40 minutes, when I noticed my boyfriend try to watch away or close his eyes I screamed baby he's hurting me, baby ask him to stop and things like that and he automatically has he eyes on me even though he doesn't want to. Even his cousin was doing a great job saying he's using me like a slut just because he can and there's nothing my boyfriend can do about it. Especially when he came in side me he dragged me close to my guy and he held my bf's face near to my legs and showed off his creampie and after that while pushing my boyfriend's free hand to the wall he grabbed me again and made me kneel down in the middle of him and my bf and peed all over my face and body saying I'm a worthless woman and it's not a surprise how worthless my boyfriend is not being able to do anything about it. He got dressed and I walked him to the door, gave him a thank you kiss. Walked back to my boyfriend who had red eyes at this point, I unlocked his cuffs and I was so happy when he said even though it hurt him a lot more than usual with my choice it made him sure why we love doing what we do to each other.