Nothing dramatic has to happen for distance to open up at home. Your schedule fills with practice, shifts and friends while their energy quietly shrinks, and the two of you end up living in the same house on different timetables. Neither side chose it. Drift is simply what happens when nobody schedules against it.

Pick one small repeating thing and defend it: Sunday breakfast, the drive to work, one show you watch together. It does not need to be deep or long. The point is that it recurs, because closeness runs on frequency more than on intensity.