Is it ok to change with my friends family at a swimming pool together ?

I've now my friend for years and his family. I am 15 so is he. He has a mum dad and sister who's 13. I was staying at there house for the weekend as my mum was away. They siad we sould all go swimming I said I had no trunks so they gave me two pairs of toms ( my friend) brifes to wear so when we got to the changing rooms it was one big girls and boys changing room no indivaul chaining room so we got to a bench then we all looked at each uther then all took are shoes of then soaks then tops bra's for girls then we all took are trousers off then tom took his brifes of I had never seen him down thear befor but it was very small snd not much hair then his mum and sister took thear pants off Jessica ( sister) was full of hair down thear more than tom then his dad then I took my boxers off I was very hairy and quite big then we wear all naked his mum past the trunks out to tom his dad and Jessica then took hers out then she past out 1 pair off brifes then anouther I put them on then his mum said do they fit ok I said they ate quit tight she said well u have gone much more into puberty than tom. We did the same on the way out. Was this ok that we saw each other naked. Thanks for reading