are you actually into it? have you talked about how far it'll go or how comfortable you both are with it? cuckolding can go about as short or far as you want it really (like flirting to straight up him finding you someone and watching them fuck you).

Tbh I'd see what your local kink community is like, and if they have safe local resources for you to access? I've never done it but thats usually what I do first. If it exists/you're comfortable that is.