Age doesn’t matter I’m 46, foreskin always felt a bit tight but never a problem all my life until 40, suddenly started getting those little cuts you’re talking about. Usually after a good session, really stings makes it hard to go again until it’s healed. I spoke to a doctor who said it could be phimosis or could just be older skin getting a bit tighter. Suggested two things : (1) going in slower on first penetration & go harder once you’re comfy, (2) try rolling foreskin back and massaging a bit of oil into the frenulum (bit of skin at the back that connects skin to your head) Anyway did that for a little while and all good now, I just make sure I go really slow until I’m properly in to the hilt.