5. Stop putting in effort
This is what usually happens when you get too comfortable with someone – you simply stop trying.
You stop complimenting them and treating them like they’re someone special. You stop putting time and thought into birthdays, anniversaries, and romantic dates.
You stop trying to impress them or make them feel good or show that you love them. Relationships take work, so even if just one person stops trying it will inevitably crash and burn.