It's pretty simple -- you can start robbing drug dealers now and work on how to pull off the "fictional" and "gay" things later.

It could be worse - If she found someone exactly like her heart throb he’s not going to be interested in her romantically… But seriously, most people have their fantasies regardless of if they acknowledge them to others or not. There is nothing wrong with that. You should consider it a positive sign that girlfriend felt close enough to you to tell you this. If she had a fantasy about someone more attainable like a neighbor or your brother then it would be cause to worry… Just let it slide by, don’t obsess over this or throw it back at her. Maybe in the future you might want to tell girlfriend one of your fantasies - But remember how you felt about this and try to avoid making her feel bad.

Use this opportunity to indulge her. Instead of thinking of it as a pain in the ass, get the same outfit, try to nail down the acting, and bring that shit into the bedroom. Just because people role play fantasies, doesn’t mean they are gunning for the real thing, but you will make her day/week/month/year for taking time to emulate it and let her fulfill it. Kudos if you use powder sugar in dime bags to mimic the drug part (in your home, don’t take that shit to the streets, it’s actually illegal in several places to sell fake narcotics even if they are just disguised as one). This is an opportunity to win points. If fantasies were that bad, many people would be arrested for sexual assault of their step sisters!