Unwanted Seder Invites
One of my more senior co-workers always hosts a seder and invites all the Jewish employees from my office. Last year, I was relatively new to town and grateful for the invitation. It turned out to be a fairly untraditional seder, the food wasn't kosher to the standard I prefer and I felt like I had to be "on" the whole time. This year, though I haven't been issued a formal invitation, my co-worker has made it clear that she assumes I'll be there. While waiting for (and dreading) the formal invitation, I got invited to a friend's house for seder. I know this would be a seder more in line with my own observance and I'm excited to go. Can I get out of going to my co-worker's house? What should I tell her?
Unwanted Seder Invites
Many people rightly feel like Passover is a time to open their homes to anyone who might not have a place to celebrate the seder. They may invite people who they're not close friends with if they imagine those guests might otherwise be without a seder. All who are hungry, let them come and eat: We may not always take those words so literally as to invite truly destitute people into our homes, but Jewish communities generally do a good job of making sure that seders are available to those who want them.
Your co-worker may be taking this approach to her Jewish staff. Last year, in fact, her invitation was spot-on based on the circumstances you described. This year, even though she hasn't issued a formal invitation, she may just want to make sure you know that you're welcome to attend and that you don't have to worry about where you'll spend seder. With the holiday a week away, it's actually a little late to be issuing formal invitations, so you're totally within the bounds of convention to have found another place to go.
You didn't indicate how you responded to her assumptions that you'd be attending her seder. Hopefully you were appropriately non-commital, and this will be a non-issue. You can wait for her to invite you for real and then say, "Thank you so much for including me again this year. I'll be spending seder with some friends from my synagogue (or whatever), but I so appreciate you thinking of me."
If you need to resolve this sooner for your own sanity, go to her and say, "I just wanted to let you know how much I appreciate you opening your home to me for Passover last year. I wasn't sure of your plans for this year when I got an invitation from some friends, so I'll be spending seder with them. I hope you and your family have a really wonderful holiday." You could even include a bottle of wine in this speech or some other gesture that feels appropriate for your office climate.
Alternatively, if it seems doable, you could find a way to work your seder plans into casual conversation. That way, you potentially save both of you from having to make excuses.
While she is your higher-up at work, it's also your holiday to celebrate however you choose. If you feel the need to be even more conciliatory, consider inviting her to your home for a Shabbat dinner sometime in the near future. That way, you establish a rapport and a reciprocity. It's also possible that when she sees the customs and vibe in your home, she'll understand that your Jewish practices don't line up. When it comes to really any invitations involving co-workers, as long as you are gracious and respectful, you've handled the situation appropriately.