how can you describe the relationship between Montag and Mildred?

Montag and Mildred are happily strangers. They've been married, have little in common, and they've grown so far apart that they can't even remember the early years. Thus, they move on complacently and go through the motions of a married couple. Had Clarisse never appeared..... had Montag never questioned..... they'd probably have gone on in this way for years.