Lilly Becker has publicly accused her former husband Boris Becker of neglecting his financial duties towards their 16-year-old son Amadeus.
The Dutch model claims the tennis legend has failed to meet court-mandated maintenance payments of £8,000 monthly.
Her partner, sports agent Thorsten Weck, has been forced to cover essential costs for the teenager.
"My boyfriend has helped me out with those basics before, and it's not even his duty. Aren't you ashamed by that, Boris?" Lilly stated in comments to the Daily Mail.
Boris Becker has been publicly accused by his ex-wife over missed payments
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She expressed deep frustration that the six-time Grand Slam champion appears unwilling to fulfil his obligations despite his continued public profile.
The accusations mark the latest chapter in an increasingly bitter dispute between the former couple.
The couple wed in 2009 and welcomed Amadeus the following year before confirming their separation in 2018.
Following the breakdown of their nine-year relationship, British family courts established the monthly maintenance arrangement.
Lilly has since relocated with her son from their Wimbledon home to Germany, citing impossible financial pressures.
"He's a different size every six weeks. Thank God he doesn't want designer gear; he's not into logos. Amadeus is a British boy through and through, but the cost of living in England on a single income was too much for me," she explained.
The move was partly intended to bring the teenager closer to his German heritage and encourage more contact with his father.
Boris Becker's ex said "aren't you ashamed?" in a brutal public barrage
| PABecker served time in a British prison after being convicted of four offences under the Insolvency Act relating to his bankruptcy proceedings.
Lilly contrasted her ex-husband's reluctance to meet basic obligations with what she described as extravagant displays of generosity.
"Let me tell you something about Boris. The last time I said to him, 'He could do with some clothes', he bought Amadeus a designer hoodie and took him and his school friend to a five-star resort in Dubai," she revealed.
"It shows how out of touch he is that he'll make these grand gestures, but he won't pay the money a court has ordered him to pay to cover the basics."
Since his release from prison in December 2022, the former world number one has remarried and started a new family.
His wife Lilian de Carvalho Monteiro, 22 years his junior, recently gave birth to their daughter Zoe.
Lilly questioned why her ex-husband has found time for "expensive holidays" and social media posts celebrating his new life whilst allegedly neglecting his teenage son.
The dispute escalated when Lilly attempted to have the existing British maintenance order recognised by German authorities last year.
Lilly and Amadeus Becker have been "neglected", the Dutch model insisted
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She anticipated a straightforward administrative process but was taken aback when her former husband contested the application.
Becker ultimately lost his appeal against the German declaration of enforceability.
"I was flabbergasted. He wasn't being asked for anything extra. Our position is that this was simply the sum that had been agreed in 2018," Lilly said.
The former champion lodged a €26,000 security deposit as part of his legal challenge, funds Lilly noted could have gone towards supporting their son.
Boris Becker won three Wimbledon titles throughout his career | PABecker has now applied to modify the arrangement, seeking to slash payments from £8,000 to roughly £1,000 monthly.
"When we were together, it was always Boris's way. Now, I think he just wants to win," Lilly observed.