They keep flirting after it stops being necessary

Most couples flirt to attract each other — in the early stages, flirtation is functional, a tool for signaling and building desire. The couples who go decades together keep flirting after they've already won. The compliment that wasn't required. The look across a room that says 'you, specifically.' The text in the middle of an ordinary Wednesday that serves no purpose but warmth. These gestures aren't necessary, which is exactly what makes them so effective. Flirting after commitment is a choice, and choices communicate more than obligations do. When you flirt with someone you've already won, you're telling them that you're still actively choosing them — that your desire for them is ongoing rather than historical. The couples who lose this habit, who let flirtation become a thing they used to do, are describing love in the past tense while still technically in the present. Keep flirting. It is what tells the body the love is still alive when the mind is busy with logistics and years.