What was this anime series and episode?

[BrianSpilner2001]

I DO NOT have a screenshot of it, but I came across an anime clip on Facebook which had a scene where one female character mentions to a male that her swimsuit is “skintight”, and then exposes her nipple to him. Next part, the male character shares a swimsuit with another female character or the same one, can’t remember. And then dive down in the pool.

I’m not sure whether it was a piece of hentai or from an anime series of some sort, but could someone please help me as soon as possible to identify that Anime series and Episode? I

Thanks.