Rod Stewart is still ''voracious'' in bed.

The 'Do Ya Think I'm Sexy' rocker may be 68, but he's still got the right moves in bed to please his wife, Penny Lancaster, 42.

Penny reportedly told a friend: ''Rod's voracious! I knew he was a ladies man, but he usually tires me out!''

Rod - who has sons Alastair, eight, and Aiden, two, with Penny - is also a hopeless romantic and knows how to treat Penny properly on date nights.

The source said: ''Rod wrote a song about Penny called 'She Makes Me Happy' and two or three times a month he'll have the nanny watch the boys so he can whisk her off for a romantic night out. Sometimes they'll just take a walk on the beach, but other times he'll treat her to a lovely dinner followed by a night of passion in a hotel.''

The source added reformed ladies' man Rod - who has eight kids with five women - can't believe his luck and would never even think of cheating on his beautiful wife.

They added to National Enquirer magazine: ''Rod never dreamed he'd have such a sexy young wife at his age. So he treats Penny like gold. This is one Hollywood couple that's in it for the long haul. They're incredibly happy and very much in love.''