Casper Smart Jennifer Lopez dress red carpet

Va-va-va-voom!

Jennifer Lopez and her much younger beau Casper Smart sizzled at the Vegas promotional screening of Parker.

In the flick, JLo plays a real estate agent who's going through some personal shiz. Good thing she has a strong shoulder to lean on with co-star Jason Statham.

The sexy Latina's Kaufman Franco gown is to die for!