Go to ace hardware and buy a shovel, borrow a friends pickup and make sure you pre dig the hole. You don't wanna be digging somewhere with a body ... I mean the cargo... in your truck bed.
poof problem solved ^_^
j/k j/k I too have a hard time letting things go
I believe your options are
1. Talk to him and explain, you simply wanted to know what the squash thing was. And you are sorry if you offended. (If you dont think he will listen and or do not want to face him then slide a letter into his locker, also explain you simply wanted a friendly conversation and after that letter you will cease any and attempts)
2. Completely ignore him and forget about the event over time.
3. Go to a different gym.
4. re consider going to ace hardware xD
I personally would try those suggestions in order 1-4 ^_^, hope that clears it up a bit but from knowing you before I feel like you already thought about and weighed those options.