Any shows where the female lead and the male lead are dating/close to dating. She's friends with the second male lead who likes her, but she only sees him as a friend. Eventually she has to lie to the male lead though to help out the second male lead in some way. The lie is found out and that causes problems with her relationship. Eventually they reconcile though.

The only one that comes to mind is Cheese in the Trap

I can think of others with the more general plot of: FL lies to the ML, causing the rift (but she's not doing it for another guy). Would that work? 

hm, the story you interpret is somehow like Secret, but the FL lie to ML because she want to protect the SL because she love him eventually FL and ML together in the end. but the genre is melodrama, so you should watch out for the more angsty the story goes.

 Rara:

hm, the story you interpret is somehow like Secret, but the FL lie to ML because she want to protect the SL because she love him eventually FL and ML together in the end. but the genre is melodrama, so you should watch out for the more angsty the story goes.

I'll check it out. Got anymore like this? I'll take ones where she does like the second male lead at first as well.

I'm Not a Robot - but the female lead is not close to/dating the male lead before the lie