While growing up, I would not describe my family as having lived a "nudist" lifestyle (nudist beaches, nudist resorts, nudist cruises, etc), but nuclear family members seeing each other nude was commonplace, and there were a few family activities that seem to suggest a borderline propensity towards what I will call "family nudism".
It seems to me that being a "nudist" suggests something more than parents and their children sometimes seeing each other naked around the house, or when together in other private locations (hotel rooms, vacation rentals, private campsites, etc). Even around the house, we didn't go out of our way to be nude. But, we also certainly would not go out of our way to cover up for fear of other nuclear family members seeing us naked (that would have seemed very silly, indeed).
There were occasions when being naked together as a family was actually intentional. Each year (spring/summer/autumn), we spent many weekends at a private family cottage on a small private lake. Swimming, canoeing, sunbathing, picnicing, and other lakefront activities were usually enjoyed in-the-nude. But again, this was generally for nuclear family members ONLY, and although there was something fun/exciting about the freedom of being naked outdoors, this was NOT an overtly sexual excitement. Although, as teenagers, my sisters did have beautiful female bodies, I certainly never experienced sexual arousal/attraction because of seeing them naked.
I said "generally" above, because my sisters and I were occasionally allowed to invite cousins and/or friends to the cottage. Depending on the nature of the specific relationships and other specific circumstances, various degrees of nudity were either allowed or NOT allowed. I remember when my younger sister invited a friend (Rachel), to whom I was secretly very attracted (I was 14.y.o., and she was 12.y.o. with the body of a 15.y.o.)... I was thrilled when I found out that her parents had agreed that she could skinny dip with my sisters! I snuck down to the waterfront to get a peek, but Dad caught me. Later that evening, Dad made me admit to Rachel that I had peeked, and he had me strip naked in front of her and my sisters (my erect penis on full display) for my punishment... (a severe thrashing with a hickory switch, that I had to cut from a tree in my birthday suit -- 30 stripes -- then, cornertime with my striped/welted ass on display for 30 minutes).
I also remember one time, when my older sister and I (she was 18.y.o. and I was 16.y.o.) arrived home earlier than expected, that we found my parents nude in the family room (their clothes on the floor) watching a movie. Not just nude, but in in the process of passionate lovemaking. And, not just making love, but Dad was taking Mom in the vagina from behind (doggie-style), and clearly enjoying his moment of climax, with moans and groans. My sister gasped, "Oh my God!" (which were also the exact words that Mom was gasping repeatedly, between her own moans and groans). Dad looked up and saw us. He just smiled while finishing his business with several final aggressive thrusts!
There is NO WAY that my parents would have planned to have us see them f--king, but they had taught us about "the birds and the bees", and they didn't react like this was the most embarrassing thing in the world. My sister said, "We're so sorry!", and we turned to leave. But, Dad said, "Don't leave. We're done now. Don't feel embarrassed. You and your brother wouldn't be alive if your mother and I didn't enjoy this recreational activity!... So, you're home early? Sit down and enjoy this movie with us." By the time we were teenagers, Mom and Dad had done a great job of teaching us to be modest, but not to be prudish about nudity and sexuality within our nuclear family, so we stayed. As our parents moved from the floor to one of the family room couches, we watched Mom use Dad's underpants to wipe between her legs, and then hand them to Dad to wipe off his still-erect penis. They sat together on the couch (naked, but covered up with a blanket), and we sat together on the other family room couch. And, as I recall, it was a very good movie.