Weddingbee boards

Dear Hive, so, I really have to invite several co-workers.  Can't really use the rule of thumb about which ones I'm friends with on the outside, because with our hours, there is no outside! I've been in this huge organization for 15 years and we all know each other pretty well.  There's very, very little employee turnover.  Okay.  I'm inviting most of the 'grown-ups' the folks (like me; hate this divide at work) on the professional side of the aisle, plus the bosses.  But there are those on the so-called "general service" side, or more clerical, but great at their jobs and we couldn't live without them.  Anyhow, I have a real schizophrenic relationship with these TWO whom I've worked with very closely for the five or so years; there's a third, but he is new and I wouldn't have to invite him).  Guy and gal, sit across from each other and tell secrets or something ALL day long via IMs; every move everybody makes and they seem particularly interested in my moves (!), which hurts LIKE CRAZY! Some days as I get close to invite time (thee weeks away), I think, yes, I'm definitely inviting these two.  Have to, and don't want to stir up any more bad blood than is necessary. And we do sometimes get on well, you know?  But things turn on a dime here.  Other days, like when they don't invite me to something or leave me out of some personal or funny group e-mail to others in the office, I feel really dejected and think why am I inviting them to my wedding?  You all advised me about a month ago to invite the witch (a grown-up) who supervises them.  I just have to, I know it.  I should also tell you we sit in an open newsroom-type space.  See each other's faces all day every day.  So what should I do?  What would you do? Maybe the answer is staring me in the face, but I just don't see it!

You guys are amazing! Such even-handed and even-headed advice! I really like it as I try to keep a cool head here with all this wedding planning.  I know I glossed over the third fellow, been here a year.. he's sweet, he obviously would be a little hurt not to be invited, but, like everybody, we have a budget and WE HAVE A LIMIT! Is it cool not to invite him (of course, I have NO prob with him whatsoever; he stays to himself and is like a third wheel around these other two).