Slow down...
Repeat what you have just done some more times. And most important: talk with him about what you like and what makes you horny.
Maybe you can alternate between differen genres, but if your goal is becoming bbc hotwife, than you should also show different reactions and engadgement: colder when not bbc (distracted, look the phone, skip...), hot when bbc (eyes wide open), lava hot when amateur wife with bbc(s) stretching her pussy (masturbate). Gradually shift to the one you are looking for.
Then talk, make comments ("so hot" "she is enjoying so much" "look at that size"). Should be clear you like what you see.
Only then you can make your move with bbc dildo (maybe you can ask him buying it) at first maybe some dildo 3some, and then more and more solo...