Do I make you horny baby?

How is it, that my husband finds the need to.....how should I word this? Aww hell. Lets just say it. Jerk off. I guess I could have chosen more eloquent words, but..... Anyway, he is married to a woman who is ready and raring to go whenever he is, on top of being adventurous and even enjoying oral sex. So what gives?! How do I know he does it? Good question. Honestly I just assumed everyone did it, and I have no problem with it except for one disgusting little fact. He leaves...evidence behind. I'll get out of the shower and lie down on the bed, grabbing a pillow, only to find a huge fresh stain on said pillow. This has happened more than once. Why wouldn't he clean up the mess? Does every guy do it this way? I'm sorry, but thats gross. And on top of it, a bit insulting. Instead of a nice afternoon romp, I'm left cleaning up his solo act. It doesn't matter how often or how wild and crazy the sex is, he still leaves his signature all over the place, like a dog marking territory. Any tips on how to solve this touchy matter would be greatly appreciated!