JK to Inkou Kyoushi SP ~Wataru Seken wa Ero Kyoushi Bakari~

The protagonist is a 41-year-old teacher who pays for sex as a hobby. He’s obsessed with high school girls.
He spends his days hitting on the girls in the newspaper club he advises, or using dating forums to contact girls from other schools, taking them to hotels, and giving them “support” money—his code word for his shady activities.
One day, he finds a girl on a forum who matches his type and arranges to meet her. But it turns out to be a trap set by the newspaper club girls, who plan to expose him to the police!
Narrowly escaping the trap, the protagonist pins down the disguised girl on the bed, a sleazy grin spreading across his face.

“The going rate is ¥2,000 per round, with an extra ¥1,000 for the hymen and another ¥1,000 for finishing inside… right?”

[Translated from dlsite]