OP: Boredom over a decade absolutely happens, especially if monotony exists. Couple of points. You said he obsesses about DS travel soccer. This tells me he loves winning and perhaps more happy when it's in dominant fashion. Perhaps tying the two together will make a spark. During the game, text him that he looks hot and make an inside joke between the two of you that if your son gets a goal or assist, you've got something "special" waiting for him at home.
Since you're both working day jobs, send him a PM or text between 10 before and 10 after the hour when you know he can look at the message, but can't do anything about it as he's entering a meeting or conference call.
PP's mentioned porn. Don't automatically look at it as bad or as a replacement. Instead, it gives you insight to what he really might want, but is afraid to ask or you might not like doing, or don't do well currently.
If he's watching porn, check the history on browser to see what type of porn he prefers. It will tell you what he'd like to do, but might be afraid to ask...or you might not be good at doing.
Finally, I must state this. Partners need frequently to push and pull each other so that their value increases in the others eyes. I'm not saying sleep with anyone else, but spend more time talking to the other dads at DS's games. Ask them what English Premier league team you should start cheering for and why? You consider yourself in shape and not ugly. If you see yourself as hot, others will too. If they do, he will as well. We always rate external perceived value higher than we do in our own minds, especially after 15 years. Change up your wardrobe a bit on the weekends and take an interests in others with a bit of bold, daring and even slightly flirt a bit. He'll notice, and will respond. Let us know how it goes. Oh, and one more thing. You need to learn a new "skill," if all he wants is one position in bed.