彼女がレズに寝取られる!?～百合にハマった恋人を、おしおきチンポで取り戻せ!!～（Kanojo ga Lez ni Netorareru!? ~Yuri ni Hamatta Koibito o, Oshioki Chinpo de Torimodose!!~）

"We were as happy as we could be."
Jun lived on his own near the university.
Arika attended the same school. They were good friends, and had become lovers.
It was a sweet time, and they spent all of it together. Jun hoped it was forever.

The Change... One day Arika went out to drink with a group of friends. Jun was also invited but his schedule did not permit it. From that day, he began to feel the distance between them as if she was hiding something. She began to act more aloof.

The New Friend...
Arika was going out with her new best female friend, Azusa.
They seemed more intimate than normal girl friends, a touch here, a look there.
Jun didn't pay it any mind. They were girls, girls did things.

Give Back My Girlfriend!
Azusa had slid right between Arika's legs, opening her slit
and mind to the beauty of girls love. Oh god, what a humiliating blow!
A man's pride is all he has, and to lose it to a more capable woman...!
He has one thing she doesn't. But is it enough to win Arika back!?

[From DLsite English]