Gitai Saimin
English title: Alien Hypnosis
Japanese title: 擬態催眠
Type: OVA
Episodes: 2
Source: Visual novel
Genres: Hentai
Studios: Y.O.U.C
Producers: Digital Works
Duration: 30 min per ep
Rating: Rx - Hentai

Shinta is just an average student. But one day, a tentacle-shaped alien suddenly parasitizes in his penis. Shinta complains about it, but the alien answers there will be no problem because it can mimic. Shinta decides to satisfy his sexual desire using this power....

(Source: Eroge Shop)