Britney Spears and bf Sam Asghari had an early Valentine's Day celebration ... chilling in a seaside Malibu villa worth $30 million!

Axar.az reports that, the 5 bedroom, 6 bath palace has amazing ocean views, which Brit's been enjoying since she wrapped her latest Vegas dates. The pad has 2 master bedrooms, theater room, gym ... and of course, a gorgeous pool and hot tub -- standard issue in the 'Bu.

The spot goes for $7,500/night, for normies, anyway -- but we're told Airbnb gave Britney the pad for free.
It looks super romantic -- because it is -- but it was also a family affair as Brit's boys were with the couple. Didn't stop her from getting into full R&R mode.