Perhaps This Couple Wants More Than Their Bull?

We are a long time married couple, both 50, and have been in a Bull-Hotwife-cuckold relationship for a year+. He’s a great Bull, really understands the Hotwife-cuckold dynamic, and gives J the best sex of her life. We all have a great comfort level in and out of the bedroom, and J and this Bull used to play sporadically a few years ago before picking things up again. Perhaps adding to this couple’s hopes for things to escalate quickly, our Bull has exclusive bareback access to J’s pussy and has since the beginning.

The Bull is single, really enjoys dominating us both, and is highly turned on by having a Hotwife-cuckold couple.

Naturally, J has developed feelings for Bull, but these feelings are proportionate to the level of involvement and are not really a threat to our stable and happy 20+ year marriage. I encourage and understand those feelings and do not feel threatened by them.

Unfortunately, the Bull doesn’t seem eager escalate the relationship beyond a once or twice a month “booty call” at our place. We (the couple) want things to progress organically in a cuckold marriage direction. At least for the near term that would include things like:
*Playing at the Bull’s place as well as ours – Just J, of course. Bull is single and lives alone. It would just make it easier for J and Bull to play more often, as this couple would prefer.
*J and Bull going out publicly once in a while to dinner, etc.

Any ideas on how to encourage this great Bull to expand the play and maybe even become a boyfriend for J?