Penis rubbing against underwear through the cage

Hello chastity experts I tried but couldn’t find much information/suggestions about this problem I have with most of my cages The problem is that sometimes when walking the head of the penis starts rubbing against the underwear through the cage, very uncomfortably so, specially since I have to walk some 5 miles every day to to work and return home:( What I did in one of my cages was put a small piece of cloth between the bars and my penis, but it is not a very practical solution as it is a little difficult to put it back in place after peeing, and change the cloth regularly for higiene purposes. Did any of you face this issue? If so, what are the strategies for dealing with it?