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Younger boyfriends have a deadline.

“Would you like to drown in me?”
Being caressed all over my body, melting deep inside me... I'm going to do something like this in place of my lover...!?
Yumina is told by the man she thought was her boyfriend that he is marrying another woman.
That's when she realized for the first time that she was being treated like a sex friend.
She couldn't say anything back then, and later she was whining to her best friend at a cafe she frequented.
"Let's make him pay for it!" Aoyagi, a cafe employee, interrupted the conversation!
In order to get back at her wedding, she says that Aoyagi will only replace her as her lover until her wedding.
He is friendly but forceful when it comes to sex, and her heart and body are gradually at the mercy of him...

English Webtoon version: https://comiko.net/series/77570/toshishita-kareshi-wa-kigen-tsuki