Alfonso Valiente - who split from Nicole's mother Rosemary when she was six but remains close to his daughter - told the Mail on Sunday newspaper: "You know about the proposal? Yes they are engaged.
"My future son-in-law is a really nice guy, really down to earth.
My family all like him. The good spirit is there."
Alfonso, 52, says he first met Lewis last year after the couple spent a week with him and his family on the Hawaiian island of Oahu and the sportsman left a good impression.
He said: "When he walked into the house for the first time he picked up one of the babies. That went down very well.
"He is sincere and he and my daughter seem genuinely happy together. Lewis is a really good guy. When they came to visit, we hired them a Jeep because he had never driven one before."
While a spokesman for 25-year-old Lewis refused to confirm their engagement, Nicole recently revealed how she wants to settle down and have children.
The 32-year-old singer said: "Do I see us getting married and having children? My head says yeah, but I'm really focused on my music now and I think that will come in time.
"I think I'll be really strict like my momma, maybe even worse. I won't let my children out of the house! I'll make them listen to classical music."
24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.
Despite being pictured visiting the same dermatologist's clinic last week, Kim Kardashian and Beyoncé did not seem like friends inside the building. Read More »
Katy Perry has reportedly told friends that she is yearning to become a mother and doesn't think she needs to be in a relationship. Read More »
20 new pics of Kate and William.
6 best pics from the royal tour!
Check out these pics of Prince George!
10 pics from Will and Kate's visit.
Kate and Will wows the crowd!
Will and Kate hanging out with Peter Jackson.
10 photos of adorable Prince George!
The royals arriving in New Zealand!
South AfricaCity PressMarket Related
South AfricaCommunicate Cape Town ITR24000 - R27000
HousesR 2 150 000
HousesR 1 495 000
HousesR 9 000 000