What is a safe way to stretch a tight foreskin?

Q: My 60 year old boyfriend is uncircumcised. When he retracts his foreskin it tears. He has very fair, delicate skin. His foreskin does not retract easily even when his penis is flaccid.
What can a man do to gradually stretch the foreskin so that it does not tear during intercourse?
A: The difficulty with retracting the [...]

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