If your foreskin is too tight to be fully retracted, it can be stretched. You might be able to do it yourself with maybe five minutes of stretching each day for a few weeks or months. You need to get two fingers into the end (little fingers if necessary) and stretch it wider. Pull hard. There is also a prescription hormone creme that can make it respond better to stretching. You'd have to see a doctor for that. Don't let him use the tightness as an excuse to cut it off. There are better and easier solutions.