I understand how you could think so. It does seem like the perfect place for a couple, but if you look at it in the right way, then you'd see that it's really the worst thing you could do. For starters, you're surrounded by dozens of other people, and you're in a loud, busy environment. Hardly the most intimate of settings for a date with your sweetheart.
This is why I suggested finding something to do with just the two of them. Playing Pokemon over a link cable, or maybe just going out to get a late night bite to eat at Wendy's or McDonald's (but not Burger King or KFC, whatever you do). Finding subtle ways of being romantic like this is what girls really like.