Answer: Stagnating stage.
Step-by-step explanation:
Mark Knapp and Anita Vangelisti developed a model widely accepted in communications as applicable to friendships and sentimental relationships. Stagnating is the third of the five stages of coming apart (differentiating, circumscribing, stagnating, avoiding, and terminating).
Stagnating happens when disagreements arise, as well as the reluctance to talk about the relationship.