Following last week's finale of The Bachelor, Underwood and Randolph jetted off to New York and California to celebrate their new love, which came after a tumultuous season of the long-running reality show.
The couple is currently back in California, where the 27-year-old former Bachelor has moved to be closer to his new 23-year-old girlfriend. Underwood documented their journey to the west coast with a travel pic that declared, "Let's go home and be normal."
The pair dined out at The Bungalow Huntington Beach on Sunday night, with Underwood sharing a black-and-white pic of an intense kiss with his girlfriend. "PDA is gross, but this was my first kiss in a bar," he captioned the sweet shot.
During dinner, the pair also hilariously attempted to feed each other.
Both Underwood and Randolph took to Instagram earlier on Sunday to share a pics of the former NFL player cuddling a cat. "Cat training is not going very smoothly," Randolph joked, while asking people to "send help." For his part, Underwood declared that he's "still a dog guy," despite his girlfriend's felines.
Earlier in the weekend, the duo headed to the beach, where they were spotted displaying some serious PDA while lounging on the sand.
When they weren't making out by the ocean, the pair posed with Randolph's dad, Matt, and some of her friends.
They also documented their time together on social media, with Underwood complimenting his girlfriend by telling her, "You look good in my hat."
Prior to their California adventures -- and after their many press stops early last week -- the couple opted for dinner and a show for their very first non-TV date in New York City. Underwood and Randolph dined at Vandal -- where they munched on cauliflower tacos and French onion soup dumplings -- before heading to see Frozen on Broadway starring noted Bachelor-franchise fan Patti Murin.
"There are two people here who are on their very first date, so we would like to welcome to the stage Cassie Randolph and the Bachelor Colton Underwood!" Murin exclaimed following the Thursday night show.
The smiling pair jumped on the stage, where Randolph was handed a bouquet of red roses as Underwood reflected on the parallels between Frozen and The Bachelor.
"Thank you so much for coming," Murin told the couple. "We're so happy for you guys."
ET caught up with the happy couple earlier this month, and Randolph gushed about their relationship. "We're very confident in where we are right now, and we're on the same page," Randolph gushed. "So, it feels good."
Watch the video below for more on the duo: