Here's the deal: Lee has warned and told Clem this guy is dangerous, her parents are gone, and not to run off. She's being doing it anyway all season and now she's kidnapped.
I think she gets now Lee was right.
Except now Lee is bitten looking for her and is going to die. The sickness comes on fast and hits hard. Duck died in less than 24 hours. Lee is going to spend his last moments looking for Clem (for as long as he has the strength).
Love or not, how can Lee not be a little resentful?
Even if they're reunited, and Lee isn't upset, this will haunt Clem the rest of her life. The older she gets the more she'll realize how foolish she's been and the more it will hurt.