Officer vs. Doctor
[Older man + size difference + genuine marriage before love + military compound in a bygone era + sweet romance]
On the very day Meng An was dumped by her boyfriend, she ran into Gu Jinian.
His military uniform showed off his broad shoulders and lean waist.
“Marry me?”
Gu Jinian smiled nonchalantly. “If you marry me, you'll have to sleep with me. Do you know what that means?”
He thought the timid little doctor in front of him would be scared off.
Meng An agreed without hesitation. “No problem.”
Gu Jinian: “...?”
On their wedding night, he waited to see how much longer she could keep up the act.
The lights went out. The woman who'd dodged even holding hands all day pinned him to the pillow and kissed him, her breathing utterly unsteady.
“You really do have a strong waist.”
The man's waist tensed.
Fine. He'd pamper her like a little sister by day, and take her as his wife by night.
Later, the whole military compound was abuzz with the rumor that even iron couldn't withstand Battalion Commander Gu's waist.
Ignoring the fact that the male protagonist became deputy commander before the age of 30, this book can still be added to the bookshelf.