A mystery businessman has emerged as a near-constant presence alongside Kimberly Guilfoyle as Donald Trump Jr’s former fiancée crisscrosses Europe pushing multibillion-dollar American energy deals.
Christos Marafatsos, 39, has appeared at so many of the US ambassador to Greece‘s high-level meetings that some foreign officials assumed he was her chief of staff.
But Marafatsos is not a diplomat nor an embassy employee but a private businessman and registered lobbyist for Greek construction giant Aktor Group.
It’s the same company Guilfoyle has repeatedly promoted as she pushes European nations to abandon Russian energy and instead import American liquefied natural gas (LNG), according to the Wall Street Journal.
His ubiquitous presence has puzzled officials across southeastern Europe and raised questions about the increasingly blurred lines between diplomacy, politics and business under the Trump administration.
Guilfoyle, 57, has taken on an unusually influential diplomatic role since arriving in Athens last fall, traveling throughout the Balkans to champion a ‘vertical gas corridor’ that would bring US LNG into Greece before piping it north toward Ukraine.
But according to the Journal, she has also persistently promoted Aktor, a relative newcomer to the gas industry that has joined forces with Greek state-backed energy company DEPA.
During one mission to Bulgaria this spring, Guilfoyle told people the Bulgarian government should work with Aktor.
Kimberly Guilfoyle, 57, is seen watching a Greek basketball match in November 2025. A man so often seen at her side in seen sitting behind her, top right. His name is Christos Marafatsos, 39. The two men either side of Guilfoyle are Panayiotis and Yorgos Angelopoulos, co-owners and presidents of Olympiacos Piraeus
Marafatsos is been walking behind Ambassador Guilfoyle when she presented her credentials at the Greek Presidential Palace last November
‘There is no doubt that this is kind of an official position of the U.S. government,’ one person familiar with the discussions told the Journal.
Sitting alongside Guilfoyle during an audience with Bulgaria’s president was Marafatsos.
His presence was particularly striking because Aktor’s CEO had flown Guilfoyle into the country aboard a private jet, according to the WSJ.
Several people who attended meetings with Guilfoyle and Marafatsos, including government officials, told the newspaper Marafatsos did not disclose his relationship with Aktor.
Earlier this month, a Journal reporter watched Guilfoyle and Marafatsos arrive together at an international energy conference in Thessaloniki in the back of a black BMW leading the US convoy.
Marafatsos slipped into the hotel through another entrance, away from waiting photographers.
His role is all the more unusual given his background.
The Maryland-raised businessman previously co-founded a Washington-area produce distributor and has been involved in ventures ranging from real estate consulting to an IMAX 3D experience centered on the Acropolis.
Christos Marafatsos sits down with Treasury Secretary Scott Bessent in September 2025, highlighting his access to senior figures in the Trump administration
Marafatsos poses inside Donald Trump’s lavish Mar-a-Lago club in Florida in another sign of his longstanding connections to the president’s political orbit at the CPAC Investors Summit in November 2024
His lobbying career is comparatively new.
Marafatsos registered to lobby for Aktor in November, just days after Guilfoyle arrived in Athens, according to federal records cited by the Journal.
Aktor has paid him $160,000 through June to help ‘establish connections’ with the Executive Office of the President, State Department and Energy Department.
He subsequently added three other Greece-linked businesses to his roster and reported more than $440,000 in US lobbying income over nine months.
Former US officials have raised concerns about the arrangement.
Robin Brooks, a 21-year Foreign Service veteran who served as National Security Council director for the Balkans and Central Europe under President Joe Biden, called the promotion of a foreign company by an American ambassador ‘absolutely problematic.’
Bringing a registered lobbyist into meetings with foreign officials, she added, ‘calls into question whether the meeting is advancing American interests or advancing some sort of private interest.’
Guilfoyle and the administration strongly reject suggestions that she has behaved improperly.
A US Embassy official said Guilfoyle traveled to Bulgaria ‘to advance American interests: increasing sales of US LNG to European partners and decreasing European dependence on Russian gas.’
The official said she remained in ‘full compliance with State Department guidance.’
Guilfoyle became one of Trump’s most prominent political allies before the president appointed her US ambassador to Greece following his return to the White House. She is seen during a Greek Independence Day celebration at the White House in March 2025
Marafatsos, seen far right, with Guilfoyle close by in a photo taken at the State Department in September 2025
Christos Marafatsos is seen hosting a discussion about crypto at CPAC in February 2025
Guilfoyle’s lawyer Jesse Binnall said she has worked with companies throughout the energy industry and has not focused exclusively on Aktor. He also said her official meetings are arranged through embassy channels rather than Marafatsos.
Secretary of State Marco Rubio described Guilfoyle as an ‘incredibly effective advocate for the President’s agenda,’ adding that both he and Trump ‘greatly value’ her work.
Marafatsos said he was ‘proud to champion commercial initiatives that advance U.S. interests and create lasting economic opportunity in Greece and Southeastern Europe.’
Aktor’s lawyers also rejected claims Guilfoyle improperly promoted the company, saying its involvement in the vertical corridor began before ‘any contacts’ with the ambassador.
Whatever the controversy, Aktor’s access has soared.
Its joint venture with DEPA, Atlantic-SEE LNG, has struck agreements or memorandums with companies across Bulgaria, Ukraine, Bosnia and Herzegovina and Romania.
Guilfoyle also helped Aktor secure a proposed $6 billion deal in Albania that, if completed, would see the country purchase gas through the company until 2050.
Not every deal is guaranteed to materialize. Ukraine’s state-owned gas company told the Journal on Friday that negotiations over future Atlantic-SEE purchases had halted.
Guilfoyle was previously engaged to Donald Trump Jr., putting her at the heart of the Trump family before their high-profile relationship came to an end. The pair are seen in January 2022
Donald Trump Jr. kisses Kimberly Guilfoyle after she introduced him at the Conservative Political Action Conference in Orlando, Florida, in February 2021
President Donald Trump greets US Ambassador to Greece Kimberly Guilfoyle during a Greek Independence Day celebration in the East Room of the White House in March 2026
Marafatsos’ relationship with Guilfoyle stretches back years.
He became involved with Trump’s political operation during his first presidential campaign and later chaired Greek Voices for Trump.
After Guilfoyle’s nomination as ambassador, Marafatsos reportedly helped prepare her for her Senate confirmation hearing, attended her swearing-in and became an increasingly close adviser.
Trump himself even singled him out during a Greek Independence Day event at the White House.
‘Good looking guy, he is,’ the president declared.
Guilfoyle’s arrival in Greece followed her very public split from Trump Jr, whom she began dating during Trump’s first term.
After photos emerged of Don Jr with Palm Beach socialite Bettina Anderson, Trump announced in December that Guilfoyle would become his ambassador to Greece.
Since arriving, the former Fox News personality has embraced the role with characteristic flair, mixing meetings with presidents and ministers with fashion shows, art galas and social media posts to her nearly two million Instagram followers.
But it is Marafatsos who has increasingly emerged as the intriguing figure at her side.
People who have attended meetings with the pair say Guilfoyle routinely introduces him simply with: ‘This is Christos.’
She has also allegedly directed people to send information or follow up with him after meetings.
One investor told the Journal he was surprised to discover afterward that Marafatsos worked for Aktor because the lobbyist had not disclosed the relationship during their meeting.
And earlier this month, Marafatsos was once again beside Guilfoyle as she prepared to address officials from nine countries at the Thessaloniki energy conference.
Before she took the stage, Guilfoyle handed him her phone – her lawyer said it was because her dress had no pockets.
As Guilfoyle’s diplomatic footprint across southeastern Europe grows, so too does the presence of the private businessman and lobbyist who has repeatedly appeared at her side, despite holding no official role in American diplomacy.
