I assume the individuals at my gym who are Muslim are likely to cover up when transition from workout clothes to shower but one individual at my gym does not. He is prone to be naked alone in the hot tub but when another man joins him he is fine until the jets are off. He immediately leaves the hot tub naked even though there is a sign to wear swim suits or towel. This individual will wear a towel if others are in the hot tub but is naked alone in the hot tub. My confusion is that its a public space so I don’t understand why he rush out when the jets are off but is fine when the jets are on. I know when the jets are on its hard to see him naked so from body language and encountering with him he is confident to engaged with others.

Is there something in the Quran that others shouldn’t see your genitals when in a public space?