Maybe its "GIRL THINK" but the major point is being missed here. It isn't so much your germs, but everyone else's that was in that bathroom and touched everything. If you wash your hands, then all is good. Unless you dragged your dick around the urinal edge, then tapped it's wee little helmet against the top of the urinal cake, you know, just a high five for the old target there, and then held the door open with your dick so your hands would stay clean, I'm thinking you are plenty clean enough for your gf to suck your pee pee.
Germs hang out on surfaces. Your dick hangs out in your pants. We hope you are wearing clean underwear!