You want proof you're right about her make her say it out loud. Have her admit it, she will probably feel excited and relieved
for telling what she's been keeping to herself. Her chocolate bar play is at most a subconscious play on what you said. If you
don't already have that black dildo for her order one for her and make sure the package has her name on it. Increase your role play scenarios with her, get that IR porn going, make her face her desires and before long she will openly express it. Let her know in no uncertain terms that you
are totally and completely ok with her being a black cock wife. Work on eliminating her inhibitions. Now if she had said to you she wished the chocolate bar was the real thing and covered your Johnson with chocolate and said she guess that would have to do for now. Then you would have had something. You still have some work to do on her but there is light at the end of the tunnel. Lets get her where she needs to be!