First, talk with your partner about what feels good AND what doesn’t. There is no shame in sharing and will benefit you both in the long-run.

Second, it’s good that you are able to retract the foreskin when it’s not erect – this means that you don’t have super tight phimosis. You may be able to work with yourself while masturbating to stretch and pull the foreskin down but it may ultimately need a doctor’s attention to provide medicine to help with stretching.