There are questions and answers on decent first dates
In a heart that is open, while guarding its gates.
But love is a fortress of blood, sweat, and stone,
And once it's been christened, don't come out alone.
On first dates, you're trying to get to know each other and learn if you'll be compatible, but usually people are a little guarded. This is saying that people guard their hearts carefully, but if you find love, don't let it end - don't come out of the relationship alone.