Well that was anti climatic.

How upset was he? Did the waterworks start—not… you know what I mean!

"It's so warm and dry down here, and I'm so thirsty. Pee all over me!" ... "Aaah! It's climbing up my urethra!" - Bino the Elephant

kinky

Not even close to a weird fetish, compared to others.

He shouldn't get upset, because not everybody is into that, but at the same time if he's that into it then you should at least be willing to give it a shot. Maybe make a compromise, if you let him do that to you then you get to do one of your things that he may not be into to him.

Yuck

Could you at least pee in a cup and pour it on him?

I would say that getting angry about a significant other not wanting to participate in a sexual act is definitely a red flag.

Hello, OP here. My boyfriend and I are very open and communicate about what we want to try and what we don't want to try. We've been together three years and pretty much will try anything as long as we are both comfortable. We were in the shower during this conversation and it started as a joke for me to pee on him and I told him I didn't want to but I think he was offended because he thought I was feeling self conscious in front of him so he felt like he wasn't doing his 'boyfriend duty' by making me feel okay with that... I know sounds strange. But we're over it and he actually doesn't want me to pee on him at all. Go figure. Thanks for the jokes and advice to you all!

just pee on him what do you have to lose its not like he's asking to pee on you

Red flag, by the way...