Legally Blonde star Reese Witherspoon enjoyed a romantic picnic on Malibu beach with her boyfriend Jake Gyllenhaal yesterday.

The intimate date doubled as a sun baking opportunity for the actress, who slipped into a skimpy blue bikini for afternoon outing.

But the smitten couple were not alone - Jake bought along his German Shepherd Atticus while Reese's pug Coco also came along for the day.

Into the blue: Reese slipped into a string bikini for an afternoon outing yesterday

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Heating up: Reese Witherspoon arrived at Malibu beach with Jake Gyllenhall to have a romantic picnic

The pair have done their best keeping their romance out of the spotlight, but there are mounting rumours they are planning to get engaged.even considering getting engaged.

A source close to Reese told the America issue of OK magazine: "They've been talking marriage for a while.

"They'll be formally engaged any day now. They want to spend the rest of their lives together.

"This is a very serious relationship."

Place in the shade: Reese and Jake, along with a male friend, call it a day

Puppy love: Reese, accompanied by Jake's dog Atticus, soaked up the sun

Jake’s producer friend Ryan Kavanaugh says the actor is head over heels, saying recently: "I just think he loves her.

"He has obviously had his fair share of dating. 

"I think eventually you come to a place where you know what you want and seeing what we saw on the set, he was certainly completely devoted to her and really loves her."

Reese has two children Ava, 8, and Deacon, 4, from her previous marriage to actor Ryan Phillippe.

The two broke up in October 2006, and Reese began quietly dating the Brokeback Mountain star the following March after meeting on the set of their film Rendition.