The Jurassic World star revealed via Instagram that he is engaged to the eldest daughter of Arnold Schwarzenegger and Maria Shriver, after less than a year of dating.
"Chris was very sweet when he proposed to Katherine, as he had a romantic speech prepared explaining how important she was to him," a source told ET shortly after the exciting news broke. "Katherine complements Chris and is very good for him."
"The couple got engaged quick but everyone around them saw it coming," the source added. "They really are a great couple that have a solid foundation. Chris had the approval of the family and everyone is excited for their union."
From their first public date to the gorgeous engagement ring, ET's breaking down their whirlwind love story.
This marked Pratt's first public date since announcing his split from his now-former wife, Anna Faris, in August 2017. The actors separated after eight years of marriage, and share one child together, 6-year-old son Jack.
"Anna and Chris have always maintained a respectful relationship after breaking up," a source told ET. "From the beginning, their main focus has been their son, Jack. Anna and Chris support each other in their new relationships and want one another to be happy."
"Katherine and Chris have been on a few dates. The two really enjoy their time together, but it's still in the early stages," the source said, adding that Pratt was introduced to the author by her mother. "The two hit it off. Chris is focused on the press of his movie and his son, Jack, but when he does get some free time, he spends it with Katherine."
Pratt and Schwarzenegger seemed to pay no mind to onlookers when they were spotted packing on the PDA and sharing not one, but two public kisses, while out and about in Los Angeles last July. The two attended a church service together and were joined by Pratt's son.
"[They] went from casually dating to spending much more time together," a source told ET at the time. "Chris and Katherine have introduced one another to their family and friends, and have been almost inseparable when they are free."
"That was a big step for Chris," the source added, of Pratt introducing his new girlfriend to Jack. "Until he knew it was more than just casual, he wasn't introducing Jack to anyone. Chris and Katherine are very happy together."
"The Real Deal"
It wasn't long before things got serious between Pratt and Schwarzenegger. A source confirmed to ET last August that the love between the two was "the real deal," so much so that Pratt felt comfortable leaving his son with Schwarzenegger.
"Chris and Katherine are a serious couple, so Jack being alone with Katherine is normal," the source said. "Anna and Chris are great co-parents and respect that each other are in serious relationships. Jack will be spending quality time with each other's partners."
Two months later, another source told ET that from the very first moment Pratt and Schwarzenegger started dating, everything "fell into place" and they were "inseparable."
"They just love each other's company and have so much in common," the source said. "They spend a great deal of time together. Chris and Katherine have the full support of her family and Maria [Shriver] feels they are a match made in heaven."
In honor of Schwarzenegger's 29th birthday, Pratt finally confirmed their romance on his own via Instagram on Dec. 13 with a sweet collage of the brunette beauty.
"Happy Birthday Chief! Your smile lights up the room," Pratt wrote. "I've cherished our time together. Thrilled God put you in my life. Thankful for the laughs, kisses, talks, hikes, love and care."
Pratt revealed via Instagram in January that he had put a ring on it. "Sweet Katherine, so happy you said yes!" he gushed. "I'm thrilled to be marrying you. Proud to live boldly in faith with you. Here we go! ??♥️"
Schwarzenegger shared the same pic to her own account, captioning hers, "My sweet love. Wouldn't want to live this life with anyone but you ♥️?."
A handful of celebrities congratulated the couple in the comments section, including Pratt's ex-wife, Anna Faris, who wrote, "I'm so happy for you both!! Congratulations!"
Shortly after news of their engagement broke, a source told ET that the couple "couldn't be happier" for the next chapter of their lives together.
"Since the two started dating it has always been easy for them," the source said. "They’ve been on the same page with everything and what they want their future together to look like. Chris and Katherine are intertwined in each other’s lives and are excited for the next step."
Congrats to the happy couple! For even more on their love story, watch the video below.