Well I have to disagree, I do think they showed them slowly drift apart. It's not like they were going to go up to each other and say "we don't have common interests let's end it all!" That just doesn't happen. Instead we saw new characters introduced and that helped the transition. Alli gets into her dance crew and we see her and Clare start to drift a little, Wesley gets a bigger role we realize he and Connor are closer than suggested last season. Aside from random Jenna/Alli friendship it made sense to me. I think the only thing that wasn't explained enough was the Connor/KC break.
As for Clare, did you miss an episode? We did see that.
