Walk with your wife or girlfriend, bring a book of poetry, an umbrella, something sweet to eat. You can even bring a thermos full of hot chocolate, or cool lemonade. Smile a lot; point at beautiful flowers or exquisite buildings. Then find a place that is private in a public space; lay out a blanket, pour your date a drink, give her some chocolate; open the book of Poetry to a poem that is romantic, and enjoy the moment together.
On the poetry First Thought:
Warning: A saccharoidal poem is hazardous to remaining cool and you may become too cheesy.
On the poetry Two:
Pablo Neruda is a good choice much better than something by Bukowski. Bukowski is great, but it is more private literature... not something I would read to get my wife feeling that warm feeling.
Here is one Poem to read together: