When I was 14 my mom made me some cut-offs out of jeans that I had worn out at the knees. They were properly hemmed and everything but REALLY short. Since I wore boxers at the time I thought that they would look stupid hanging out from the leg holes, so for the first time in my life I tried freeballing.
I liked to go on long bike rides at the nearby college because it had miles of pathways amid the greenery and campus buildings, so one day I went while freeballing in those shorts. I realized right away that there was no way I could keep everything in - as I pedalled the hem of the shorts crept up my thighs and my shaft and balls kept slipping out. The leg holes were a little wide and there just wasn't enough material to keep me concealed.
I continued to try to cover up but in the end gave up. Dozens of people must have seen my cock and balls that afternoon.