If she is into being shared, set her up with a younger fit white guy. Get her into playing with other guys then see if she changes her mind. If she is not turned on by BBC then going from Vanilla sex I.e. not being shared, to being shared by BBC maybe a huge leap for her. Start sharing her then work your way up from there. if she’s into it, great…..if not don’t ruin your marriage by pushing her or she may replace you completely. Talk with her tell her what turns you on and what turns you on about it,…..see if she is open to the idea.