When it happens, what does the husband do?
....He should do what makes the 2 of you comfortable him doing. It also depends on why you're doing this to begin with ... to meet a need he can't or doesn't desire to give you, or to arouse added sexual excitement to your sexual marriage.
....Once the 2 of you have set the parameters for your playing with another man, its important that both he and you get what you expect from it. Things to consider:
1_ will the activities be done at your home, the bull's home, or motel
2_ will condoms be used
3_ will the bull agree to allow hubby to be present if he wishes
4_ will hubby participate, and in what way ... 3-some, filming/taking pics, watching, masturbating
5_ who will choose the bull and how
6_ will fantasy play be involved ( ie: humiliation, pregnancy, cock locks, involvement with the bull, creampie eating, cuckold training, etc)
....The whole point of these activities are to enhance your marriage, not damage it. Have a
safe word established that each of you can say that secretly tells the other things aren't going the way you desired/expected, and that the activity should cease as soon as possible.
....Explain to your prospective bull that the 2 of you are novice at this activity, thus the bull may have a lot more understanding/tolerance to the conditions the 2 of you initially set up. You want to discover these issues before the activities begin, if possible. Respect is a 3-way issue here ... that's important.
....If the 2 of you have never done any type of swinging, I really encourage you to attend some hospitality parties at some swing/adult lifestyle clubs. As much as men often think they know what they want, they do very little long range planning to the consequences. Once he sees you being kissed or 'felt up' by another man, he may decide he's just not ready to go the full way with intercourse or oral sex.
....Good luck ...
....