Kikenbi Neratte!? Haramase Gakuen

The protagonist is a handsome boy who is popular with girls. He feels a growing desire to have sex inside him, and come on to the girls. They pretend to be not interested by the idea, but his narrative skill makes the actual action possible.
And he gets obsessed with the ecstasy of the sex and creampie cumshot. On the other hand, girls have a strong rivalry among them, and that also pushes them to go further...
And he wonders, "what if they become pregnant?"

(Source: dlsite)