1(MLB)

An Au were new classmates(ocs or characters from other animes/shows/etc) join the heroes class and they attract attention because of their good looks(and maybe some could be famous or something).

Alya, Marinette, Lila and some others planned to approach the new classmates after the class ends but they are surprised that once the class ends said new classmates make their way to where Chloe and Adrien had been sitting.

They are even more surprised when one of the new male classmates kisses Chloe's cheek and sits beside her with his arm around her.

The others all say their hellos to the duo with them hearing some calling Chloe their cousin and even one(could be Felix if you want to make him good) called Adrien his cousin.

It left them very confused but thankfully Nino was able to steal Adrien later from the group and they asked him how he knew the new classmates to which Adrien said they all knew each other since kids but the others had to move to their parents birth countries when they were around 10.

They still kept in contact and Chloe had started dating the boy who kissed her for a year now besides them having been engaged by their fathers since they were babies.

Which lead to Alya asking about Chloe acting like she liked Adrien which made Adrien laugh before explaining that she did that to keep other guys away from her and girls from Adrien as Chloe was dating someone and Adrien preferred man over woman.

Being sincere, this is just an idea that came to my mind because of my love for Chloe and a few fics I read last night that made also want to see Chloe and Adrien being friends besides having other friends(and lovers) who actually cared about their well being so anything else would be up to the writer