Dice, lemme tell you a little something about guys. We have few qualms about sticking our penises into odd places. I have a buddy who tried sticking his into one of those water jets in a hot tub. I read a news story about a dude who pulled over to a pumpkin patch, cut a hole into a ripe pumpkin, "adulterated" it, and was caught for indecent exposure by a lady cop. And I'll bet plenty of guys have tried jerking off into a banana peel, or "creaming" a Twinkie.
Nothing abnormal about any of that. Just guys being guys.
By the way, Ygg, what manga is that picture from?