LeBron and Carmelo -- The Double Dinner Date

LeBron James celebrated his girlfriend's 25th birthday last night with a romantic double date in New York ... alongside fellow NBA superstar Carmelo Anthony and his wife ... and TMZ has the footage.

The foursome was all smiles as they left the Waverly Inn in NYC -- but the biggest question ... WHO PAID?

The Waverly Inn ain't cheap -- but LeBron is in the middle of a 6-year $110 million contract and Carmelo recently inked a deal with the Knicks worth $65 million for 3 years.