Jessica Simpson and Eric Johnson are seeing a tantric sex therapist.

The 33-year-old mother-of-two is said to be even closer to her fiancé since they have been getting advice from the expert in the Indian arts of Tantra meditation, which can see couples having sex together for hours while they meditate.

A source told the National Enquirer magazine: ''While it sounds like it's all about sex, tantra is all about intimacy and also has a spiritual element.

''It's more like a yoga session mixed with couples' therapy. They do breathing exercises and then the therapist encourages them to discuss their sexual fantasies. Jessica says it's helped them open up in ways she never imagined.''

Jessica - who has sons Max, 19-months, and Ace, six months with Jason - has recently been on a health kick to lose her baby weight and her diet combined with the new tantric practices have made her feel in better shape than ever.

The source added: ''Jessica swears she has more energy, and her skin is constantly glowing. She's telling friends she's found the fountain of youth.''