here is all the details i can remember! it was a multi chaptered manga. there were two women that had a really close friendship. both of them had frequent boyfriends here and there, but they enjoyed playing with each other a lot. like they'd tease the other in public or do it in somewhat crowded places. their relationship felt very natural and loose despite all the sex and they loved each other a lot even if they were with other men.
i remember two scenes very vividly: in one of them, they were doing it on a bed. one of them was doing her from behind with her fingers and i think she said something like "huh, so this is the view men get to see regularly... its beautiful". then she told her "hey so i heard it feels really good from both sides. wanna try?" and then she does it anyway and the bottom squirmed a lot and made both of them fall off the bed... they just laughed it off. the other scene was just them in the afterglow after doing it. the moon was shining through the window, and one said "you look beautiful under the moonlight". i think that may be perhaps related to the title of the manga but i can't for the life of me remember what it was...