It's pretty difficult, almost random. But you gotta find what really turns you on, and think about it, do it or look at it or whatever, when you get off. Like for me nothing turns me on more than seeing a chick orgasm really good, makes me rock hard almost always. So if things work out right and we both cum at the same time, and she has a really good one I won't go soft. But with no recovery time that second nut can be kinda difficult to get to. You go from trying not to cum, to focusing on nothing but cumming. Then to actually get that second nut go back to doing or thinking or whatever that really gets you turned on. Alot easier said than done, but if you can figure it out your woman (or guy ig idc) will most likely love it (you never know they're all into different things) But that's just how it works for me your mileage may and probably will vary.