My partner and I have a perfect romantic relationship.

Perfect can mean flawless. It can also mean fitted: a key is perfect for a lock without being an impressive object in its own right.

That second sense is what long couples usually mean. Not that nothing goes wrong, but that this particular arrangement of two difficult people turns.

Which means the flaws are not evidence against it. Their terrible sense of direction and your inability to let a discussion end are part of the shape the fit was cut around. The imperfections are inside the perfection, not opposed to it.