Kimberly Kane & I are professional dominatrixes, and we're also your girlfriend's best friends. Your girlfriend wants to have a gangbang in our dungeon with big studs. You come to us & describe how your girlfriend wants to live out her fantasies of fucking men with bigger cocks than yours. She wants anal, double-penetration, rough sex, and cum showers. We listen with amusement, knowing where this is headed. You want us to talk her out of it.
Kim & I look at each other & laugh. You've come to the wrong place. We encourage women to live out their fantasies. In fact, we facilitate it. We explain that you need to learn to be supportive of your girlfriend & all of her needs. Since you have such a small penis, it's reasonable for your girlfriend to want larger men. You have no right to deny her anything. If you do, she'll leave you.
We ask if you're going to be ok with this, and you insist that you will, but we don't believe you. So we're going to ensure that you participate in the action. Technically your girlfriend won't be cheating on you if you're there & involved, so we're hosting this gangbang & you're required to attend. You won't be attending as one of the studs of course. No no no. We have lots of huge, hung studs to satisfy your woman. You'll be enlisted as a fluffer & cockslut. You'll watch the love of your life get pounded by better men, and you'll help her by fluffing the studs while they're awaiting their turn, rimming their assholes, and licking the cum out of her pussy & ass. You'll suck the men's cocks clean, and some of them might even fuck your ass while they wait for another go at your woman.
We'll be in attendance of course, keeping you focused on pleasing those studs so that your girlfriend is happy.