Source: Bang Showbiz NewsHeidi Klum and Seal are putting on a brave face for their children this Christmas.The former couple - who announced their split in January - are planning to spend Christmas Day (Dec 25) together with their four kids, Leni, seven, Henry, six, Johan, five, and two-year-old Lou, and are determined to act civil despite their stormy relationship.A source told the New York Post: "They're trying to be co-parents and show up for their children. They have been trying to work it out, mainly for the kids."They have been talking on the phone regularly." Heidi is currently dating her bodyguard Martin Kirsten and revealed she loves how wonderful he is with the kids.She said: "They like him very much. This is also one reason why I'm so fond of him. He's been helping me for four years now. And he takes wonderful care of the kids. He plays with them, he protects them. I trust him."The model admitted that she is madly in love with Martin but doesn't want to flaunt their relationship because her beau prefers to keep a low profile.She said: "Yes! I'm in love! Martin is not hiding. He's just not the sort of guy looking for the spotlight. He prefers to stay in the background. There will always be people who will criticise whoever I live with, what kind of clothes I wear or what hairstyle I have. At the end of the day, you have to do what makes you happy. That's the rule I live by."