Drilling Rig

I was invited with my dad to help drill a well. That morning I was getting ready to go and got dressed in my usual clothes which consist of loose silk shorts and a t-shirt. Only thing missing was my underwear since I don’t own any. My folks are pretty cool and don’t care what I wear or don’t wear. I left with my dad and got to his job. We got in the rig and went to the drilling site. He got everything set up and told me to relax since it will be awhile. I sat on the rig by my dad and he started the machine. The whole truck shook and he told me no worries and it’s normal. He pressed a lever and the machine started. The truck was bouncing while shaking side to side. By then I realized I need underwear. My dick was trying to rip through my shorts while bouncing everywhere. Within a few seconds my dad asked if I felt a draft. I was confused and looked down. I was bouncing outside of my shorts. My dad told me I will be better off in the truck. Beat red I said sure and got in. I felt like I was going to cum so I took my shorts off and enjoyed the ride. About 20 minutes later I was soaked and not by sweat. Then I heard my dad saying right behind me “looks like you enjoyed it’ with a huge grin. I knew at that time what was going to happen and why I was invited on a job site. I agreed to go a couple more times along with my brother.