Looking for romance books where the FMC’s ex later dates her sister (forbidden/angsty trope)

I’m looking for romance books with a really specific trope. Basically: • The FMC dated a guy in the past. • They break up. • Years later he ends up dating (or engaged to / married to) her sister. • The FMC and the guy still have unresolved feelings and fall for each other again. [...]