Amanda Seyfried is planning her older sister's wedding.

Amanda Seyfried

Amanda Seyfried

The 29-year-old actress, who is dating Justin Long, is very excited to host her sibling Jenni's nuptials at her farmhouse in Stone Ridge, New York, in August.

The blonde beauty told the June edition of Vogue magazine: "She's with the best guy and it's going to be great - better than my own party. All the attention is going to be on her, and I'm going to slip away and enjoy myself."

Jenni, 32, added: "I never had a dream wedding in mind, but Amanda just got really excited about it and took the reins. It's very touching."

The 'Les Miserables' star adores the rural home, which she bought last October, but has confessed she will think twice before taking on demanding roles regardless of the pay packet.

She explained: "They paid me too much money and what I should have done was walk away.I bought a house with that money! But making movies is two solid months of twelve, fourteen-hour days. I mean, it can ruin your relationship.

"And if you make too many bad decisions in a row, people don't come knocking anymore."