The person doing the kiss animation should face either left or right. The person doing the kiss_rear animation is the opposite- if you need them to face right then you do it:
@CHARACTER is kiss_rear and CHARACTER faces left
Or [ if they need to face left]:
@CHARACTER is kiss_rear_animation and CHARACTER faces right.
And whoever’s facing towards the camera [ doing the regular kiss_animation ] should be one layer behind the one doing the kiss_rear_animation.
Does that help?