They've been together forever.
They actually do finish each other's sentences.
They're always there for each other, even when times get rough.
They enjoy the same pastimes.
They celebrate their relationship.
They always seem to be on the same page.
They have a healthy physical relationship.
They give each other this look:
They're not afraid to try new things, like role reversal.
They feel safe in each other's arms.
They have more fun just staying at home and being together than going out.
They're comfortable with PDA.
They know open communication is the key to a successful relationship.
They're partners in crime.
They support each other.
They're completely inseparable.
They have the same sense of humor.
And they have similar taste in general.
Their love is unique.
They plan to be together for eternity.
They are basically married.
Their love is the standard to which romantic relationships are compared.