Just a few days after the reality star turned 21, the pair were spotted heading into Polacheck's Jewelers, a luxury jewelry shop in Calabasas, California.
The two didn't seem to pay any mind to the photographers, holding hands as they made their way into the store. Kylie looked chic in cropped jeans over a black metallic bodysuit, completing her outfit with a pair of strappy heels and trendy sunglasses, while her rapper beau kept casual in a T-shirt, black pants and bright yellow Jordan sneakers.
Following their trip, Kylie took to Instagram to give fans a better peek at her sexy top, while showing off her perfect highlight, that was created using products from her Kylie Cosmetics collection. Eagle-eyed fans also noticed that the lavish present Travis gave her for her birthday -- a vintage Rolls-Royce! -- was in the background of the pics she shared:
A source told ET that Kylie's birthday "was more than she could have imagined."
"Kylie was overwhelmed with the numerous parties, love and support," the source said. "Kylie was happy to have everyone close to her, to celebrate her birthday and all the success she’s accomplished in her young age."
"Travis referred to Kylie as his 'wifey,' but it was just a term of endearment," the source added of the Instagram caption the 26-year-old rapper used in his tribute post to Kylie. "Although the two are madly in love, they are not married."
Get an inside look at Kylie's star-studded birthday bash here -- including all the details on her sexy outfits -- and watch the video below for more on her romance with Travis.