AceShowbiz -

Dean McDermott expresses his happiness after his wife Tori Spelling gave birth to their fourth child, a baby boy they named Finn Davey McDermott. The "Kiss the Bride" actor writes a touching letter to welcome his son "into this crazy, whacky, amazing world full of joy, good times, bad times, love, loss, friends and foes."

"I've watched you grow in your mom's belly for the last 37 weeks. You started off as just a little tiny bump, and now you're this incredible little being that I see move and kick and literally sit up in mama's belly. I wonder what you're going to look like, what your little voice is going to sound like, what kind of personality are you going to have," he says.

Among all the questions about what his baby will be like, Dean states, "I'm wondering what flavor you are - if you're a boy or a girl? Like your sister Hattie we decided we wanted to be surprised (again) as to what sex you're going to be. It was the most amazing surprise, when Dr. Jason held up your sister and declared, 'It's a girl!' "

Dean promises to be the best dad for his son, "I'll be there for your first tears, your first bump and bruise. I'll be there for your first steps, your first words, and your first day at school. I'll be there for your first broken heart, your first award, your first car, I'll be there for your wedding day, and I'll be there for your firstborn."

"I'll be there first. For you. With all my love and devotion, I will fight tooth and nail to give you the wonderful life you deserve. Because you have made my life wonderful beyond my dreams by being my child, a little angel that has found your mother and I and blessed our lives with beauty and grace. I will give you my last breath, as you have given me my first."

Introducing baby Finn to his brothers and sisters, Dean gushes, "They're always full of love, laughter and energy. Quite frankly they're absolutely bonkers too, but you're going to love them. Mom and Dad are a bit kooky too - that's just how we roll. Not to worry though, we'll grow on you after a while. So strap on your onesie, because it's going to be a wild ride."