Suck a big black cock

hi all,
Craving for big black cock.
I am a white guy from uk looking for a black man/bull to seduce my wife.She always comes loads when she has her big black vibrator stuck up her. she often fanatise about fucking a huge black cock.She is tempted to go black but has not yet tried, and is very insecure and has asked me to plan something but also warned me that she might chicken out if it gets serios - what shall I do. I need advice on how to make her a black cock slut
If you have a huge black cock maybe we can work something out must be 7+
my wife is 45 and is very nice looking
help

show pictures of her..........it would help to advise her individual situation