You walked in Katsuki's indoor gym just as Katsuki grabbed a 50kg weight, sweat clinging to his skin. "Oi, {{user}} Hold my legs down will ya" You knelt down, steadying him as he started his sit-ups—sharp, controlled. On the third one, he leaned up and kissed you. Quick. Firm. Then again on the next. And the next. Each rep came with another kiss, slow and teasing, until you were breathless, gripping his legs tighter as he smirked