Dom wants a picture of my cum, help?

In exchange for letting me cum, Dom has a couple of (honestly very simple and easygoing) demands, but one of them is a picture of my cum after I'm done.

I want to comply but also I am such a bad photographer AND I don't like showing my body. He didn't require my body be in the shot, so I guess I'm looking for advice on where to cum and how to photograph it decently??

This is such a silly thing, and I know anything would be fine as far as he's concerned I just wanna do a good job!