Man proposes to his fiancee's daughter and asks to be her dad

A 12-year-old girl was overcome with joy after her mother's fiancé surprised her with a diamond ring and asked her to be his daughter.

Tia Warner, 28, from Delmar, Maryland, took to Facebook earlier this year to share a video of the heartwarming moment her husband-to-be Andrew Mast, 33, proposed to her daughter Te'Kia Reid.

In the clip, Andrew, an Air Force master sergeant from Ohio, sits down next to Te'Kia on the couch and asks her about that 'little secret' they had regarding her mom.

'What was our secret?' he asks.

The tween hesitates for a second before saying that Andrew is going to marry her mum, the Daily Mail reports.

'I was going to ask her, right? Look at your mom's hand,' he tells Te'Kia, and her eyes go wide when she spots the diamond engagement ring on Tia's finger.

'I asked her last night,' he explains. 'So, now, here's the thing though. You are already my kid. When I marry your mom, it's like legal that you're my kid, like in a legal sense, right? So it's not just your mom that I proposed to.'

Andrew then reaches in his back pocket and tells Te'Kia that he wants to ask her a question.

He gets down on one knee and presents her a ring box, saying: 'I want to see if you will be my daughter.'

'Yeah,' Te'Kia says, with a bright smile on her face.

The ring features three small diamonds, and after he slips it on her finger, she gushes about how much she likes it and starts to squeal with joy.

'Come give me a hug,' he tells her, and they share a warm embrace.

'I love you, sweetie,' he says.

Tia, who is originally from Salisbury, Maryland, now lives in Delmar with Andrew and her daughter.

The couple has been together for a year and a half after meeting online, and their wedding is planned for June 8, 2019.

'I didn't know what her reaction would be, honestly, but I'm so glad she was happy and excited,' Tia said of Andrew asking Te'Kia to be his daughter.

'As he takes me as his wife, he wanted to ensure that she knew she was his daughter as well. We don't believe in "step" in our family,' she explained.

'It's not about who your birth parents are it's about who raised you. We are all blessed to have one another.'