Of course forgiveness is a strong word and we're talking about rap lines in here, so it's not that serious. But I think you know what I mean. Not just 'bad' lines, 'cringe' lines, but lines that whenever you listen to them you think "come on Em, why?" and make you want to skip to the song.
* Fuck my last CD, that shit's in my trash (Cinderella Man)
* I'm a shit stain on the underwear of life (Won't Back Down)
* My last CD was ehh/wack (Not Afraid)
* Puke
* I guess it's time for you to hate me again (Medicine Ball) (song as a whole is Em trying too hard).
Couldn't find an example on Infinite, SSLP, MMLP, TES and MMLP2.