Wiz Khalifa and Amber Rose Welcome Son Sebastian Taylor

The rapper and his fiancée Amber Rose welcomed their first child, son Sebastian Taylor Thomaz, on Thursday, Feb. 21, the proud dad announced via Twitter.

“Happy Birthday!!!” Khalifa — born Cameron Thomaz – writes. “Everyone welcome this perfect young man into the world.”

After confirming the pregnancy while walking the MTV Video Music Awards’ red carpet in September, the couple posed for a series of intimate shots that showed off the model’s budding baby belly.

“I’ve decided that I’m going to have an all-natural water birth. No medicine,” the mom-to-be, 29, told XXL at the time. “I want those bragging rights! The next time Wiz has a stomachache … I’ll say, ‘I popped a baby out all natural!’”

It seems the couple’s son had other plans though, as Khalifa, 25, Tweeted a photo of himself dressed in hospital scrubs and a mask.

In January, Rose celebrated pending parenthood with a colorful baby shower surrounded by close family and friends.

Earlier this month, the couple attended the Grammys, where Khalifa joked that he’d like his lady to “stay pregnant forever.”

Amber Rose and her fiance Wiz Khalifa are reportedly expecting their first child in January 2013

 The model and her fiance Wiz Khalifa are thought to be expecting their first child in January 2013 and Amber wants to move up their wedding date to October to avoid getting married when she is heavily pregnant, according to MediaTakeOut.com.

Rapper Wiz proposed to Kanye West's former girlfriend earlier this year and although the pregnancy was a surprise, the pair are said to be thrilled about the baby and are already making a number of lifestyle changes to prepare.

A source told RadarOnline: "Amber and Wiz unexpectedly got pregnant, but they're really happy to be starting a family together"."Amber's already had to make some big lifestyle changes, like not smoking cigarettes anymore. As a model she's used to having a thin waist, so this is going to be an adjustment for her."

Speaking about the proposal previously, Wiz revealed he showed Amber the "real" him when he popped the question.

He said: "[It was] real simple. It was in the morning time. I just rolled out of bed and got the ring out of the laundry room. Didn't brush my teeth. I was sober, I gave her the real me.

"I didn't cry. But she was crying so much she didn't know what to do. I was like, 'Say something, yo! I didn't let her take time to think about. Knew she was going to say yes."