I am fortunate enough to have had a girl do it in my mouth a little.
An ex was once drunk and was sat on my face while I was pleasuring her. She really enjoyed it came a bit too hard and a bit of wee came out. I found it a real turn on so she dribbled a little more while I carried on. She really liked it as one off but it was never mentioned again (pity). She claims to remember nothing of the incident. I'd love to relive it some day.
As for the picture, there can be no question of forced compliance. As much as I find the idea exciting, I'm not sure I would be able to accommodate a girl rel