Heidi Klum's new husband Tom Kaulitz is an ''extra dad'' to her children.

The 46-year-old model tied the knot for the second time with the musician earlier this week, following their secret wedding in February, and the 'Project Runway' host feels grateful that Tom understands her children - Leni, 15, Henry, 14, Johan, 12, and Lou, 10 - with ex-husband Seal are her ''first priority''.

A source close to Heidi told PEOPLE: ''Heidi's relationship with Tom was easy from the start because he was accepting of the priorities in her life. She made it clear that her first priority is being a mom.

''He considers himself an extra dad. It's been important to Tom to just be respectful of Seal. Tom is very mature and acts beyond his age.''

''Tom has endless energy and is very playful. He plays sports with Heidi's boys and is involved in activities that the girls enjoy. Heidi loves his energy and take on life and feels very grateful that she met Tom.''

Heidi and Tom held their second round of celebrations over the weekend on luxury yacht, Christina O, off the Italian island of Capri.

During their ceremony, the bride wowed in a beautiful white strapless wedding dress with detachable puffed long sleeves and a veil, while Tokio Hotel guitarist Tom wore a cream suit and a blue shirt.

They were then joined by their guests at the La Fontelina restaurant on the island.

Heidi and Tom couldn't keep their eyes off one another and packed on the PDA as they were seen kissing at the dinner table, with the former 'America's Got Talent' judge placing her hand on her husband's lap as they shared a sweet embrace.