There are lots of awesome things you could do in this world with your friend next year. It's ok to eat a registration fee. Here are five things that the two of you could do that would be better than running Boston by yourself:
1. Find, or create, a doable 2-person Guinness Book of World Record, and get t-shirts made after you achieve it. You will become legends to your friends on Facebook.
2. Go to Mexico and buy an assortment of performance enhancing drugs, and test them out in a race South of the Border. Who knows? Maybe your friend will find the cure to their slowness disease and the two of you can run Boston every year for the rest of your lives.
3. Make your own running adventure that hasn't been done before. Choose a scenic place to do it and takes lots of photos. Once again, you will become famous on social media and set a FKT.
4. Find a winnable race for your slow friend and let him beat you across the line. Make a slow-motion video of the train-up and race using Chariots of Fire music.
5. Do something at the end of May called the Bob Marshall Wilderness Open. Grizzly bears galore. Nothing like friends confronting danger together and stepping out of their comfort zones.