My Dad would totally freak out, he'd be like 'pfftt, ok'. The worst that ever happened was when i was running out of the ocean and my dad was sitting on the sand and he tells me my white swimsuit shows my pubic hair! It went see through.
I knew a girl who went topless in front of her dad with her mum, when they were on some island vacation- i could NEVER do that. We're not THAT close, haha. Her dad is into yoga and stuff and beleives in having no shame when it comes to your body, so he didn't care. My Dad is too much of a prude.