Animating TWO different avatars..

How can an object animate two different avatars at once?
For example, if u make a kiss-script which makes two people kiss, how would you explain to the script which avatar you want to animate.

The function llStartAnimation only takes one parameter (the name of the animation), but how do you tell it which avatar you want to animate??

llStartAnimation operates on whichever avatar the script has animate permissions for. You will need a script for each person, most likely by having two poseballs linked together.