Texas billionaire Sid Bass is facing a federal lawsuit from his former partner, Oona Sperr, who alleges the oil heir abruptly ended their decade-long relationship and broke promises of lifelong financial support. The complaint, filed in Manhattan federal court, accuses Bass, 84, of a pattern of infidelity and abandoning long-term partners for new flames.
Sperr, a New York interior designer, claims she dedicated over 10 years to managing Bass's households and accompanying him globally, in exchange for assurances of financial security and shared ownership of acquired properties. She is seeking at least $400 million in damages.
According to the lawsuit, their partnership began in 2014 when Bass allegedly invited Sperr to join him permanently. During their relationship, Sperr described their life as "Bass Land," encompassing residences in New York and Colorado, a private jet, and a private island. Bass reportedly referred to Sperr as "Mrs. Bass" and gifted her significant jewelry, including a 25-carat diamond and a 20-carat emerald, similar to stones he had given previous wives.
The relationship reportedly soured on September 3, 2024, when Bass allegedly told Sperr, "I want a separation. You are to pack and leave." Sperr claims Bass initially offered a settlement including $50 million, a Manhattan home, and continued support for her elderly mother, but later withdrew the offer.
Sperr alleges that Bass denied another woman was involved, but weeks later, she claims to have overheard him speaking intimately with art adviser Althea Viafora Kress. The suit further alleges that Viafora Kress demanded Sperr's possessions be removed and that Bass cease direct communication with Sperr.
In August 2025, Sperr claims to have received an email from Bass's account announcing his marriage to Viafora Kress on August 9. However, Sperr alleges this marriage was a "coerced ceremony" and a "sham marriage," asserting that Viafora Kress exerted control over Bass's communications and finances.
The lawsuit also references Bass's past relationships, including his first marriage to Anne Hendricks Bass and his second marriage to Mercedes Tavacoli Kellogg Bass. Sperr's legal team portrays these past relationships as evidence of a pattern of Bass replacing partners, citing his alleged affair with Mercedes while still married to Anne, and a subsequent relationship with Patricia Zohn Pfeiffer.
Concerns about Bass's health are also noted in the complaint. Sperr claims Bass suffered mini-strokes and that a 2019 doctor's assessment indicated abnormalities consistent with Parkinson's disease. His drinking, she alleges, increased during the pandemic, affecting his judgment and memory.
Robbie Kaplan, Sperr's attorney, stated, "This is a case about broken promises. Sid Bass is a billionaire at least four times over. Oona is the woman who spent a decade making Sid’s life convenient — abandoning her career, managing their shared homes and affairs, caring for him through his serious illnesses — all because Sid agreed that he would take care of her and her 96-year-old mother no matter what. After accepting all the benefits, Sid abruptly ejected Oona, breaking his promises to her. Because Sid has failed to keep his word, Oona, now 64 years old, had no choice but to bring this case."