I rarely see "intact" cocks in the U.S. I began trying to keep my foreskin retracted whenever in locker rooms while in school or changing rooms at public swimming pools wherever someone might view my cock. I wanted my glans to be exposed like everyone else. My skin would roll forward and cover my glans almost immediately. It didn't take long to discover the more I pulled my skin back, the plumper and shinier my glans appeared, and that would help keep the skin back longer. I enjoy observing other guys glans, so I'm proud to show mine.
I've tried many methods to keep my foreskin retracted over the years, and the only thing that works for me without discomfort is wearing glans rings. I'm not aware of any sensitivity loss. I still enjoy gently caressing my glans with foreskin retracted, enjoying the sensations without having my cock erect. Don't know for sure, but believe my glans has become larger by trying to keep it uncovered.