That requirement sounds like Hong Sisters’ dramas to me, I feel like they almost always have a steadfast fl & a somewhat confused ml (with the exception of The Greatest Love).
I can’t tell you whether or not you’ll find them annoying since that’s a subjective metric, but Delightful Girl Choon Hyang & My Girl both have smart & loyal (at least emotionally) female leads and male leads that spend some time wavering between the fl & 2fl.