NEW YORK >> Is that love in the air or french fries? White Castle, KFC and other fast-food restaurants are trying to lure sweethearts for Valentine’s Day.

It’s an attempt to capture a bit of the $3.7 billion that the National Retail Federation expects Americans to spend on a night out for the holiday. Restaurant analyst John Gordon at Pacific Management Consulting Group says it appeals to people who don’t want to splurge on a pricier restaurant. And some customers enjoy it ironically.

White Castle, which has been offering Valentine’s Day reservations for nearly 30 years, expects to surpass the 28,000 people it served last year. Diners at the chain known for its sliders get tableside service and can sip on its limited chocolate and strawberry smoothie. KFC is handing out scratch-and-sniff Valentine’s Day cards that give off a fried chicken aroma to diners who buy its $10 Chicken Share meals or a bucket full of Popcorn Nuggets.

Panera Bread wants couples to get engaged at its cafes; those who do can win food for their weddings from the soup and bread chain. And Wingstop sold out of its $25 Valentine’s Day kit, which came with a gift card and a heart-shaped box to fill with chicken wings. The company says 1,000 of the kits were gone in 72 hours.