What causes exhibitionism? are childhood experiences factors?

im proud of my body cos i work-out and have a model-like physique, slim and msucular, smooth. And whenever i feel good about my body, i get the rush to expose it to other people cos i want tem to find me y. I also love the feeling of being nude around people cos it feels so liberating. i love going to common showers bcos i can be nude in front of others. i love being exposed both to men and women. and i love going to sports complexes and swim in my speedos cos it feels almost nude. i wish there are nude beaches in my country. What could have casued this behaviour of mine? one time i was walking in a pool area in my speedos and i saw groups of girls staring at me and i loved it. am i a certifiied ? or am i just proud? is this normal? im 20 years old, gay, male. im dont really expose myself in a vulgar wayl ike what others do, iwant to expose myslef in a way that would not seem like a get doing it so you may notice my activities are kinda subtle,