Alessandra Ambrosio Shows Off Her Amazing Body Playing Beach Volleyba -

Alessandra Ambrosio Playing Beach Volleyball -- Spike!

Alessandra Ambrosio is serving up a little sex on the beach ... looking stunning as ever during a game of beach volleyball.

We got pics and video of the retired Victoria's Secret supermodel putting her amazing curves to work, having fun in the sun over the weekend at a beach in Los Angeles. Mother nature gets an assist on this one for turning up the heat so Alessandra could turn heads in a skimpy black bikini.

FUN IN THE SUN

The mom of 2 is about to celebrate her 38th birthday ... and she's looking fine as hell! We're convinced this MILF could still work the runway.

Alessandra isn't afraid to get down and dirty ... diving for balls and laying it all out on the court. Sexy beach vball sessions are kinda her thing.

The icing on the cake ... Alessandra shaking her cake by the ocean!!!