Kim Kardashian marks major relationship milestone with Lewis Hamilton

Kim Kardashian has just taken a huge step in her relationship with Lewis Hamilton.

The 45-year-old reality TV star has been romantically linked to the 41-year-old British racing driver since February, but it's been reported that they've actually been an item since December.

Since then, the couple have been teasing fans with snippets of their relationship both with public outings and on social media, with the latest update in the ever-developing saga seeing Lewis appear in not one but two of Kim's most recent photos shared with her 345 million followers on Instagram.

Amidst the sea of photos and short clips in the mum-of-four's jam-packed photo dump, posted Monday (1 June), was an adorable selfie taken by Lewis of the pair out and about riding bikes together along New York City's West Side Highway.

Lewis' second appearance came in the next slide on the hefty carousel post with a short video of the pair posing for the selfie taken on the bikes as Kim seemed to have some issue with her balance before slightly veering off into her boyfriend's bike in front.

She captioned the sweet photo dump: "lately."

It didn't take long for fans to rush online and share their elation over the 'hard launch', with one fan gushing: "So cute!"

"Adorable," penned a second as a third chimed in: "She looks so free with him, and it’s so refreshing to see!"

A fourth beamed: "Love this for her!"

"Love them together," mused a fifth as a sixth echoed: "Love seeing her happy again!"

Another praised: "They make a really cute couple."

And a final fan added: "Kim looks happy and Lewis does too. It’s a fine romance."

Kim and Lewis' romance sparked in December last year at a New Year’s Eve party in Aspen, followed by a romantic UK getaway in January of this year.

Throughout February and March, the couple jet-setted between Paris, the Super Bowl, and Arizona, before showing up together in Tokyo and at Coachella in April.

Kim's posts come just a few days after they finally went public by holding hands in New York City and blending their families together for a group outing.

Lewis introduced Kim to his mother last Thursday evening (28 May), per the Daily Mail.

The Formula 1 driver treated his mum, 71-year-old Carmen Larbalestier, to a dinner at Los Angeles restaurant Nobu alongside Kim and her family.

Fans were clearly equally as buzzing over this major relationship milestone, with one social media user exclaiming: "Kim will make a great daughter-in-law!"

"I'm glad Lewis has a wonderful mother who understands what is truly important in life," commented another as a third chirped: "Kim meets Carmen. How nice."