The "Watch What Happens Live" host, 51, shared a sweet photo Tuesday of him and his son shot by his pop star pal John Mayer — and in the caption he gushed over "what a lovely boy" Benjamin is.
The black-and-white pic finds the Bravo star holding his son in his arms and gently kissing him on the head.
"One year ago tonight, I sat alone in a hospital room with my newborn son pondering our future. I didn’t know then how his smile would brighten my day, what simple joy each new progression of his growth would bring, and most of all what a lovely boy he would become," Cohen wrote.
"I am so grateful to my surrogate in California who made this all possible, and for every day of our first year... and can’t wait for the next. Happy Birthday sweet little Ben," he added along with the hashtag #dada.
"There is a comfort in knowing that he's there waiting for me," the new dad told Savannah Guthrie and Hoda Kotb. "I went out for my first night away from him, just for dinner with friends the other night, and I was sitting there and I realized, 'Wow! I love it that he's there at home for me.' It's an anchor. It's my family. I was like, 'I love this feeling.'"
"I look at him the way I used to look at Instagram," he joked. "I just sit and stare at him. I'm like, 'Well, this is more interesting than a bunch of hot guys on my feed.'"
Cohen enjoys being a dad so much, he's even considering expanding his family.
Happy birthday, Benjamin!