Chromis kissing?

[GreenSpottedPuffer]

I couldn't get a good picture yet but two of my chromis look like they are kissing constantly. They face each other and then, well, it looks like they kiss It also kind of looks like they are nipping each other mouth to mouth but not in aggression. Or kind of like they are cleaning each others mouths?

Has anyone seen anything like this?

I will try to get a picture.