Samantha Ronson surprised actress Lindsay Lohan with a wedding proposal during the couple’s beach getaway in Cabo San Lucas, Mexico two weeks ago.

According to Britain’s Star Magazine, Sam presented Lindsay with a $100,000 Cartier diamond band as the couple enjoyed dinner under the moonlight.

“Sam brought Lindsay down at 9pm to a huge dining table laid out by the water’s edge,” says a spywitness at the Esperanza Hotel.

“Sam really went all out and even arranged for a group of Mexican singers to entertain them with songs.”

“It was a gorgeous ring with a big diamond that Sam had bought before the holiday. Sam asked her if she would marry her and the waiter popped a champagne cork as Lindsay accepted. It was such a beautiful setting with perfect weather and was really romantic.”