GF surprise joins in shower, I have to pinch

I don't know why I am sharing this but it is Friday so what the hell.

I have been dating this girl for about two months (no pics) and things are going well. I get to her place last night after dinner and jump in the shower. I start to take a piss in the shower like every guy does. My piss is stark yellow because I am dehydrated or something.

Mid piss I hear the curtain open and she starts to climb for a little surprise. I immediately pinch it off and start kissing her so she doesn't notice the yellow water in the tub by the drain. She starts playing with the old one eye and I am doing everything I can to not piss on her and her hand.

Because I have to piss so bad I can't get it up. I don't want to piss because it won't blend in with the shower water because the color. She ends up getting frustrated and gets out. As soon as she gets out I piss all over her shower.

I crawled into bed and we didn't say much. Now I don't know what the hell is going to happen. Thank goodness she didn't try giving me head in the shower.

Uh, tell her you had to go to the bathroom and you were going to when you got out of the shower so her "surprise" was unexpected, but not unwelcome. She can always do it again. And reciprocate by offering her some oral in the shower :)