I won’t be casually nude around family, but being naked in front of my dad (such as on a surfing trip recently, while changing out of a wetsuit) is no big deal to me. My dad and I are not shy around each other. Same with me and my older brother. Around the female members of my family though, we are more private. Just had a discussion about this with a friend; she was saying she and her mom can be nude around each other, but others were saying that was weird to them. It just depends on your family and what you’re comfortable with.
Being casually shirtless around family has never been an issue, though. But that’s one of the perks of being a dude. 😛