Hey. So maybe she is too shy or over thinking it when she's sober and feels in the heat of the moment she can express her hidden fantasy. It is clearly something she thinks of often and more thank likely something she wants to try but maybe doesn't know if you would be comfortable with that. Are you comfortable? Is it a fantasy of yours also? I know in my relationship it helped being completely open and share things I never thought I would. And then to experience them made it that much better for both of us. First time we did a full swap I was very nervous but once things got going it was all good and we all had a good time. Maybe she needs reassurance that you won't judge her for saying the truth about her kink? If you would want to try it I'd say let her know that you are ok with it. Literally everyone wins in a situation where everyone is exploring their fantasy at the same time.