MyObject make Visible
+On Right mouse button Either single or double clicked
MyObject make Invisible
+ MyObject Is visible
+ MyObject Opacity Less than 100
MyObject Set opacity to MyObject.Opacity+100*TimeDelta
Bit clunky, but it works: on click the object is made visible, which makes it fade in. On right click I make it fade out using the Fade behavior, then after it is done, it is set to Invisible (otherwise it just loops). So, whenever the object is made visible, it fades in. I don't know, this seems a bit complicated, plus it keeps checking for the condition instead of just executing it once.
Surely there is a more elegant solution? We'll see after I get back from visiting mom - she's down with flu.
Thanks for the help so far!