Is it normal i want to see my sister naked?

i swear it is NOT a sexual thing infact were both girls its just a sort of curiosity thing. like that ive known her so well for so long but ive never seen her naked is just weird to me and i think seeing someone naked is part of knowing them well. ive seen her boobs a few times like at the beach but i think since were so close i should be allowed to see her fully naked. i think someone being naked is like a whole new part of them and it shows you something of them they cant tell you so sisters who have been together a long time should see eachother naked. but i dont want to just tell it to her ill feel weird! its so easy with my friends cuz i shower with them and skiny dip with them sometimes but with my sister the one i want to see naked the most she never does any of those things with me. like her house has a pool and i tell her it would be fun to swim but i forgot my bikini and she says ok whatever you can swim naked if you want but im wearing my bathing suit. so i was naked by the pool and shes not and i asked how do i look and spun around and she smiles and says great and i say oh you look great too but were not really equal here and she laughed and said sorry but my vagina stays covered up no matter what. and im like come on you even need to hide it from your sister and shes like yep even from you. if i talked about it even more she would know so i just laughed with her but really i was super furstrated! im just curious to see her body is all i think ive earned the right to deserve it over the years because were close but its not as easy as with my friends and im getting furstrated becasue i cant figure out how to make her do it for me without making anything weird. ive told this all to my very very best bff and she said she had the same thing for her cousin but her cousin is alot more open then my sister so it was easy for her to get it. so i think its normal but maybe i have weird friends lol. can anyone give help?