There are a TON of bare breasts and buttocks in each episode, but they never show any pubic areas nor any sexual activity.
The main character is well known to be a pervert, which is also shown when he fights (especially against women) in which they usually end up in their birthday suits.
One of the main characters, Rias Gremory, always sleeps naked and when Issei wakes up, her boobs and nipples are in view.
In the outro, there are girls gyrating in lingerie and pole dancing.
A female character wears a barely there costume, revealing her breasts and buttocks. She wears this costume almost her entire screen time. She is not sexualized.
There is a lot of sexualized nudity in this anime, more then your average Ecchi.
Sexualised nudity is pervasive, but actual sex is never shown.
There is frequent sight of young naked women, including full close-up shots of bare breasts and buttocks.
The main protagonist, Issei, is obsessed with naked women, and he often lusts after them.
A man grabs a woman's breasts forcefully and she moans orgasmically.
A priest attempts to rape a young woman; he grabs her breasts and puts a gun into her crotch.
Many power attacks (especially by Issei) shred the clothing of multiple women, leaving them nude.
An antagonist is said to have his own harem and despite being "engaged" commits sexual acts with many of the girls.
The Ecchi contains more nudity than most others.