It's incredibly hot to hear her say that!! It is possibly even hotter when she asks you for permission (first time) and you have only seconds to decide. If you say yes, you humiliate yourself and your relationship with her, but if you say no, you completely kill the mood. Perhaps you reconfirm with her, "is this really what you want?" What then if she nods in affirmation? What if she says it is up to you. Meanwhile you see that you'd need a crowbar to get him off her, out of her, and then you realise that you are too late. He will have her all the way ...
I've been in this position and there was nothing I could do. She wanted him inside her and he was going to have her all the way. I was completely taken aback and watched it happen. On the one hand, it is nothing, and on the other hand, nothing will be the same thereafter.
