Evil SML does bad things to main leads

Are there any plots like this? The FL and ML are dating and the SML is in love with her, but she only likes him as a friend. He causes the ML to believe that the FL is cheating with the SML who she's friends with. This causes a huge misunderstanding and the FL is desperate to fix it and hates the SML for doing what he did. 

Like towards the end of Loving, Never Forgetting.

lol Loving Never Forgetting was the first drama I first thought to recommend, but anyway here are some you might check out

• Inborn Pair - SML is actually a good guy but he does something so stupid that made the main couple break up. a very long family drama, but a must watch.
• Love in Bloom - very very very long daily korean drama, so it needs a lot of patience to watch
• Delightful Girl Chunhyang
• Falling for Innocence
• Hi School Love On
• Iris