Trapped in Bed With My False Destiny

Koharu Satou, a hotel employee, has a boyfriend, Rintarou Orisaka, whom she loves dearly. They were childhood friends who made a promise to see each other again after he had moved away as a child, and they finally did. Shy and inexperienced, Koharu allows her him to take charge during sex. However, things take an unexpected turn when Koharu helps out at a new hotel and bumps into the real Rintarou. She learns that the man she's seeing is actually Rintarou's twin brother, Outarou.

"I'll stop if you tell me you love me," Outarou says, as he violates her with pleasure now that his secret is out...

(Source: Pachika, translated)