I have two co-workers, both of whom got married several years ago, and they both invited me to their wedding. One wedding I went to and the other I didn't. I see and talk to them everyday in the office. Is the proper thing to do, to invite them to my wedding? Having another 4 people (them and their spouses) at the wedding won't really make or break our budget so that's not an issue. Part of me would feel bad if I didn't invite them. What do y'all think?