Well, it's not a race or competition. Odd that you call it one-sided -- as if the two of you, individuals that you are, are supposed to move forward at the same pace and have the same experiences as you go along in your lives.
Just remember that the goal should be to connect with other people and develop those relationships naturally, not to keep pace with each other and make sure that you both are equal in "acquiring" lovers. That kind of focus would create a dynamic of objectifying the people you meet, because you would then see them as a thing to have in order to say that you and she are "even" now. Honor the people you meet by seeing them for who they are and cultivating any new relationships on its own terms, not as an addendum to your marriage.
In other words, now it isn't all about you and her anymore. You will have others to consider and no one you meet would want to be a prize that you seek in order to compete with her. Not saying that is your attitude, but it is something to keep in check.
That being said, it is quite common for one partner to find a lover before the other does, and very often the woman in a M-F partnership is the one who finds a lover first. There are a gazillion posts here just like yours.
I say, be thankful that you are both not involved with others at the same time just yet!!
This is new to you both. One of you having an additional partner, going through NRE and such, changes to the time you spend together, and the emotions that arise, will already have a huge impact on the dynamic between you two, so now you have the opportunity to absorb it and adjust to it slowly. Take your time, allow feelings to come up and handle them, examine your boundaries and agreements, and adjust accordingly. Then when you meet someone, you both will have some experience and know what to expect in dealing with all the changes and the new energy of sharing emotional and physical intimacy with an additional person in your life. No need to rush it!
Last edited by nycindie; 02-07-2013 at 02:02 PM.