How do I make my penis more sensitive to sex and increase then intensity of my orgasms?

27 M. No I don't masturbate often. I usually use a fleshlight if I do so I doubt deathgrip. I have sex as often as I mastjrbate with women. But sometimes I'm just not that sensitive. Like I don't always feel that much during sex or blow Jobs. My orgasms are also like a sneeze and very brief.