As to the "back and forth" of emotions, well, polyamory is an adventure in a way. Try to see it as a rollercoaster ride, strap yourselves in, and get ready for some ups, downs, twists, and turns. You both know each other so well, and have a sense of each other's rhythms, but when you have additional people involved, there will be energies that are new and less predictable. I think the ups and downs of emotions will pretty much be something you can count on for a while.
Originally Posted by hyperskeptic
Baby steps seem about right.
Diving in and having sex with other people - as a "fling" or as a transaction - seems likely to prove disastrous . . . especially if you understand polyamory to be not primarily focused on sex.
^ I disagree.
I am often the loudest in arguing that poly's main focus is not sex, but I don't see anything wrong with either of you experiencing sex with others first as a way to get comfortable with opening up your relationship. That can be the baby step you need to take. It's all relative, and I don't see how a fling will "likely" be a disaster, necessarily, if everyone has their eyes open. Not that you should use people to experiment with, but if a fling or FWB situation avails itself for one or both of you, and there is interest and a connection, why not? Maybe start out as open and ease into poly.
Everyone is different regarding how they connect with others. Sex can be the first step to developing relationships and deeper intimacy. I have always been someone who usually has sex on the first or second date, and many meaningful relationships have come out of that (I fucked my ex on our first date and we were married five months later). If a difference in libido is a main reason why you are embracing poly, then why not? A fling/FWB often develops into something more, and you can confront your feelings about emotional connections getting into the mix as you move forward. I would recommend that you hook up with people you really like, respect, and trust. A key word in FWB is "friend," and that word means a lot to me, but it's okay if the connection is more casual than a "love relationship" is and has no intention of going deeper than a friendship with a physical aspect.