Thanks for the replies.
Ok, let me add on... I know that for some it comes naturally. I feel for me it might although it hasn't come up yet. But how about those who it doesn't come naturally for? Say the S.O. who agrees to open their relationship up but not partake in the "openness". They need to "find" compersion and although we'd love to believe that it comes as easily as "I want you to be happy" would, it probably doesn't.
So was it just as easy for your partner(s) to feel compersion? For the non-poly side of a poly relation, does it just "come naturally" or did you have to work on it and if so, anything in particular that helped you/them?
Life is about the journey and not the destination,
so what better way to know life
than to wander all the roads and paths set before you.