LOve to see a video of the white wife being black bred and then of her pregnant later. Never seen one like that so in my mind it seeems this are staged videos on the whole
Watch the film with her and ask her to fantasy being with a balck stud. Buy a black dilod and use that whiel watching (give a real name to the dildo). Tell her how you like the idea of being a cuckold to black. Good luck and let us know how it goes
You should keep mentioning that you know you are on the small side and mention that there are bigger ones out there -especially black - then buy her a big black dildo to emphasis teh point