J2J:
I remember seeing the photo of the third couple, Bai Lu, Luo Yunxi, and Li Jia Hao. No private ones with the second couple.
I might wrong, but Bai Lu is usually friendly, she seems polite and distance towards Cheng Du Ling. It could also be Bai Lu was too busy talking to Sun Zhen Ni.
When watching the BTS, you can see that CDL comes across a bit cold and distant. If I remember correctly there was one BTS where YunLu were happily doing their karaoke when CDL was acting a sad scene. And they were like oops..shhhhh. Annoying the Bitchang? Maybe? I dunno, sometimes signs are very subtle. It could be they don't like each other and just keep it professional. That's life, you cannot be friends with everyone. Can try, but not always possible right?
2nd CP would think that they deserve more publicity, but most of the publicity went to YunLu. Actually if the 2nd CP acted better than YunLu, people would want more of them. Just like when Xixi was 2nd lead in AOL, I wanted to see him more than the main CP leads. He was that good.
Anyways...just talk, nothing confirmed, so lots of speculation from what we can see from their interactions in the bts and private time together.