I feel like someone "important" was in that vehicle when Shou kissed Kyouko. Either Ren was in that vehicle and saw it, or maybe he wasn't in the vehicle and didn't see it. Either way I think he is going to find out.
I hope we're near the ending of the Manga. I honestly can't stand all these cliffhangers. :/ We're already at chapter 223 and Kyouko STILL hasn't found out Ren is Kuon... Considering we found out what feels like decades ago.
I think it would be good character development if Ren did see it but was able to cast aside any petty feelings of jealously to stand by her and comfort her. It would be great progress from his old phone throwing self. I hope he saw it and he just sweeps it under the rug. He knows how Shou is and he saw her miserable expression. I'm gonna be disappointed if he throws another tantrum when something much bigger is going on.
Nemu is awesome.