ANSWER: This is from the first episode of Oppai no Ouja 48.

ANSWER: This is from the second episode of Kanojo x Kanojo x Kanojo.

ANSWER: This is from the first episode of Kakushi Dere.

ANSWER: This is from Seikon no Qwaser 2, episode 11. Not hentai, very ecchi.

ANSWER: This is from the second episode of Ikusa Otome Valkyrie G.

ANSWER: This is from Love es M.

ANSWER: This is from the second episode of Wanna SpartanSex Spermax.

ANSWER: This is from Spocon!, episode 1.

ANSWER: First episode of Kanojo x Kanojo x Kanojo.

ANSWER: Oppai Gakuen Marching Band Bu

ANSWER: @HornyDragon42 Absolutely false, I recognize those tits. This is from Oshaburi Announcer.

ANSWER: This is from the second episode of Saishuu Chikan Densha Next.

ANSWER: This is from the first episode of Shoujo kara Shoujo e.

ANSWER: This is from the third episode of Kuroinu.

ANSWER: This is in the first episode of Menkui!

ANSWER: This is from the first episode of Koikishi Purely Kiss.

ANSWER: Ane Yome Quartet, second episode.

ANSWER: Fifth episode of Joshikousei no Koshitsuki.

ANSWER: This is from an eroge called Do You Like Horny Bunnies? 2. Heres a link to a set of gifs that contain some from this eroge.

ANSWER: This is from the first episode of Bible Black New Testament.

ANSWER: This is also Ane Yome Quartet.

ANSWER: This is from the second episode of Ojou-sama Yomeiri Kousou.

ANSWER: First episode of Tsundere Inran Shoujo Sukumi.

ANSWER: I couldnt find anything but torrents last time. ntp.so/KMRPRW1A7ZM9I

ANSWER: This is from To-love Ru Darkness, not hentai, but pretty ecchi.

ANSWER: Its from an ecchi anime called Kanokon. Not porn. I have no idea what episode its from though.

ANSWER: ntp.so/UZPTGRU2ZWYZH