The Manchester United footballer has been pictured flanked by Sergio and Jorge Ramalheiro as he joined United stars for a team bonding lunch in Cheshire.
The brothers served with an elite special forces unit in Afghanistan and protect Ronaldo and his family away from the world of football.
The siblings, part of a set of triplets, were also in a police unit responsible for guarding politicians and judges.
The Portuguese twins joined the army from school and ended up progressing to the special forces.
An insider told the Daily Mirror newspaper: "Sergio and Jorge dress elegantly and look very normal. They can mix with the crowd but they are quick to think, see and act at the right moment."
Ronaldo is believed to have round-the-clock protection and the footballer has previously been looked after by a former MMA fighter and an ex-elite paratrooper.
The football superstar recently revealed that he and his girlfriend Georgina Rodriguez will be welcoming twins.
Ronaldo confirmed the news on his Instagram account alongside a picture of himself and Georgina laying in bed together and holding up a picture of their recent scans.
He wrote: "Delighted to announce we are expecting twins. Our hearts are full of love - we can’t wait to meet you #blessed (sic)”
Georgina posted the same photo on her account, and wrote the same caption.