The wife and I have had this experience once. She was seeing a vetted younger guy and she mentioned to him that she wanted me to join their next adventure. They met at a hotel, I was sitting in a chair in the corner of the room, he came in and said hello then we all had a few drinks- she was playfully flirting and touching his arm and chest often. She then kissed him and she slid her hand down to his bulge, stroking him over his pants, he then took her top off and she unclasp her bra and her amazing huge tits fell. He began sucking on them and slid his hand down to her cameltoe where he slid his fingers up and down.
They took off their clothes as I was stroking my bwc in the corner, they made their way to bed and he layed her down. He had a 7 inch cock, slender cock but she liked it. They were kissing and he slid the tip of his cock into her wet pussy. He fucked her for about 10 mins missionary, I undressed completely and was still stroking my cock. She then climbed on top of him, it was at this point that I grabbed the astroglide and approached her and pushed her forward.
I put lube on her tight asshole and my thick cock and told them not to move, I put my cock in her ass and thrust forward, had to get the timing right with her an him, as he was thrusting I was pulling out slightly till we got into a rhythm, I shot a torrent of hot cum in her ass in about 10 mins, he pulled out of her and came on his own chest and stomach,
she orgasmed shortly before that. It was one of the hottest times we’ve had.