Does staying married for a long time require you to hold your tongue more often than you did when you were young?

Why is it often so challenging to mediate conflicts between a partner and a parent, and what strategies can help improve the situation?
I spent 7 years with my boyfriend. We are separated. He doesn’t put DP on WhatsApp, but after 4 months now, he is putting his DP. Why is he suddenly showing his DP to me? Am I thinking too much?