HI,
Congratulations on that sweet date. Good luck.

If you have a week before your date, you can do some crunches and exercise. Make sure to drink lots of water everyday. Eat more of veggies and fruits. Drink green tea and go for a light diet.
There are exercises to flatten those love handles and I'm sure this will be a huge help for you.
Wearing a shaper is okay too.

Just enjoy your date and be confident about yourself. Just go with the flow and don't be nervous.