THEME: first words of phrases describe,
in order, the progression toward marriage: SINGLE, DATING, ENGAGED, JUSTMARRIED
BTW: The theme is the only interesting aspect of this mundane Monday mystery. It is a shame that such a theme was wasted on a puzzle denuded of clever cluing. Even puzzle neophytes and speed solvers would not be burdened by a dram of creativity.
As mentioned here before, "creative" and "easy" are not mutually exclusive.
RATING:

Three grins = Loved it; Two grins = Enjoyed it; One grin = A bit bland for my taste; One teardrop = Not much fun