It looks like the triggers for the conversation with Robin about how you're having sex with the soccer boys don't actually have anything to do with whether or not you've had sex with any of the soccer boys. Might be something about exhibitionism, or the showers at the old building, or playing a dare game, but you can have an extended sequence of Sammy explaining that she's fucking them and Robin assuring you she's fine with it while Sammy is still a Pure Virgin.
On an unrelated note, is there any way to get rid of beer in your inventory without drinking it? I hate the intelligence debuff from being an alcoholic, but it doesn't go away unless you go seven days without any alcohol, if you're carrying any beer Sammy will automatically drink one every few hours, and I pick up beers while scavving faster than I can get rid of them. When I try to give them away as gifts nobody accepts, and I'm not aware of any place to sell beer, so all I can think is to just chug until I pass out over and over again which seems... like the incorrect way to deal with an addiction.