Female lead gets caught up in the moment and kisses someone else

The 2 main leads are dating, but this other guy who the female lead is close to is pursuing her. He sweet talks her and she gets caught up in the moment and lets him kiss her. She never goes past one kiss. After that though she feels incredibly guilty and she rejects the guy. She keeps it a secret, but the male lead finds out and gets mad. She then basically tries her best to win him back and does.

Something like this was in Boys over Flowers 

 Kdramalover203:

Something like this was in Boys over Flowers 

 Thousand_Paper_Cranes:

I thought that, but In boys over flowers, he sees it when it happened and broke up with her, so he doesn't find out later? are you trying to find this drama or be recommended one?

They weren't dating in Boys Over Flowers. The  main guy just liked her. She liked both guys and was sorta in denial about liking the main guy.