The comic is expecting his first child with wife Lara Stone and the couple have become so close to Simon since the comic joined the judging panel of 'Britain's Got Talent' he hopes his baby doesn't resemble his pal.
Speaking to the Daily Mirror newspaper about becoming a father, he joked: ''I'm really looking forward to being a dad, the whole experience.
''I'm looking forward to seeing the baby for the first time, seeing this little person who's a mixture of you and the person you really love. But hopefully it will look like Lara and not Simon Cowell.''
David has always loved kids and he cannot wait to finally have a son or daughter of his own.
The 41-year-old comedian thinks the impending arrival is already having an emotional effect on him as he struggled to hold back tears during a recent visit to London's Great Ormond Street Hospital for children.
He added: ''I've always found the hardest thing when I was going round with presents was that I was trying to cheer up the kids but I struggled to not get upset myself when I walked into the room.
''I think it might be even more poignant now I'm about to become a father myself, but I'm also already an uncle.
''I just love kids so much anyway. Obviously you'd hate anything to happen to them, even if they get a cold you feel terribly sad and the thought of them being really seriously ill is just awful.''