This is one of those moments that is actually three moments. Simultaneously.
It’s a moment for him. He’s emptying his thick seed inside of her. Filling her. Telling her, “Yes! You are mine and I am the man who owns your pussy and, just to make it clear to you, I deposit inside of you all of this creamy cum.”
It’s a moment for her. Feeling her pussy being pumped full of his hot sperm, warming her inside, coating her womb with his seed, the penultimate climax of giving herself to him - her man - the person in her life who makes her feel like a woman.
And finally, it’s a moment for sissy. Watching her wife and her man fuck. Hearing their grunting and groaning as he takes her. Fucks her. Owns her. Fills her. And then, as he pulls out, sissy sees the oceans of sweet cum flowing from her wife’s freshly fucked pussy and realizes that, finally, it is her time. Her time to show her wife that she understands. Understands her man’s role in her life. To own her pussy. To fulfill her. Her wife’s need to be taken by a real man. And sissy’s role. To support her wife. And to clean them both afterward.