{"id":425735,"date":"2026-09-04T04:12:34","date_gmt":"2026-09-04T04:12:34","guid":{"rendered":"https:\/\/www.newsbeep.com\/us-tx\/425735\/"},"modified":"2026-09-04T04:12:34","modified_gmt":"2026-09-04T04:12:34","slug":"ex-girlfriend-sues-fort-worth-billionaire-sid-bass-for-400m","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us-tx\/425735\/","title":{"rendered":"Ex-girlfriend sues Fort Worth billionaire Sid Bass for $400M"},"content":{"rendered":"<p>            <img loading=\"lazy\" decoding=\"async\" class=\"responsive-image\" src=\"https:\/\/www.newsbeep.com\/us-tx\/wp-content\/uploads\/2026\/09\/Sid Bass-Oona Sperr.png\"   width=\"1200\" height=\"674\" title=\"Fort Worth oil heir Sid Bass and his former partner Oona Sperr on a trip to Venice, Italy in November 2015. Sperr sued Bass for at least $400 million in federal court this week.\" alt=\"Fort Worth oil heir Sid Bass and his former partner Oona Sperr on a trip to Venice, Italy in November 2015. Sperr sued Bass for at least $400 million in federal court this week.\"\/><\/p>\n<p>        Fort Worth oil heir Sid Bass and his former partner Oona Sperr on a trip to Venice, Italy in November 2015. Sperr sued Bass for at least $400 million in federal court this week.<\/p>\n<p>            U.S. District Court for the Southern District of New York<\/p>\n<p>A former girlfriend of billionaire oil heir Sid Bass claims he backed out of financial promises made to her after he married another woman, according to a federal lawsuit filed this week.<\/p>\n<p>The 98-page lawsuit, filed in a New York federal court by Oona O. Sperr, seeks at least $400 million in damages from Bass, and also names Bass\u2019 wife, Althea Viafora Kress, as a defendant.<\/p>\n<p>Sperr, 64, and Bass, 84, were partners for roughly a decade starting in 2014, and during that time, Bass bought her a diamond ring worth $2.1 million and the couple frequently held themselves out as married, according to the lawsuit. They owned several expensive properties, including one in Fort Worth, traveled together and \u201cspared no expense on the lavish life\u201d they shared, attorneys wrote.<\/p>\n<p>At the start of their relationship, Sperr verbally agreed to give up her interior design career in favor of managing the pair\u2019s homes, overseeing renovations, caring for Bass and representing the couple socially, according to the lawsuit. In return, Bass allegedly agreed to provide lifetime financial support and maintenance to Sperr.<\/p>\n<p>The couple were so entwined with one another that they shared the same bank account and planned their wills and end-of-life care together, according to the lawsuit.<\/p>\n<p>But, as Bass\u2019 cognition and judgment deteriorated due to \u201cexcessive consumption of alcohol and early signs of Parkinson\u2019s,\u201d Kress began to groom him with the aim of gaining access to his fortune, attorneys for Sperr wrote in the lawsuit.<\/p>\n<p>When the relationship between Sperr and Bass eventually ended, Bass committed to continue providing financial support, care and property to her even though they were separated, according to the suit. Ultimately, though, the promised support was altered \u201cbeyond recognition,\u201d and some aspects were repudiated altogether, Sperr\u2019s attorneys claim.<\/p>\n<p>The initial agreement was that, in the separation, Bass would give Sperr a $50 million lump-sum payment and two properties in New York, and continue to care for Sperr\u2019s mother, according to the suit. In a later agreement, Bass altered the financial promise to $5 million annually for 10 years, imposed non-disclosure agreements, and proposed that Sperr remain as a tenant in one of the New York homes instead of owning the property, the lawsuit states.<\/p>\n<p>In part, Sperr alleges that Kress has taken full control over Bass\u2019 household and finances, and isolated him from lifelong friends and employees, attorneys wrote in the suit. For that, Sperr is suing Kress, alleging tortious interference with a contract.<\/p>\n<p>Sperr learned of Bass\u2019 marriage to Kress last summer in a six-sentence email that bore the subject line \u201cnews,\u201d according to the lawsuit.<\/p>\n<p>\u201cThis is a case about broken promises,\u201d Sperr\u2019s lawyer Roberta Kaplan told <a href=\"https:\/\/www.nytimes.com\/2026\/09\/01\/nyregion\/sid-bass-divorce-settlement.html\" rel=\"Follow nofollow noopener\" target=\"_blank\">the New York Times.<\/a> \u201cSid Bass is a billionaire at least four times over. Oona is the woman who spent a decade making Sid\u2019s life convenient.\u201d<\/p>\n<p>Representatives for Bass declined to comment Thursday afternoon.<\/p>\n<p>        Related Stories from  Fort Worth Star-Telegram<\/p>\n<p>                <a href=\"https:\/\/www.star-telegram.com\/profile\/288629615\/\" rel=\"nofollow noopener\" target=\"_blank\"><br \/>\n                        <img decoding=\"async\" class=\"author-thumb\" src=\"https:\/\/www.newsbeep.com\/us-tx\/wp-content\/uploads\/2026\/09\/1788495154_756_LillieDavidson-Profile Cropped.jpg\" width=\"400\" height=\"400\" alt=\"Profile Image of Lillie Davidson\" loading=\"lazy\"\/><br \/>\n                    <\/a><\/p>\n<p>                <a class=\"author-name\" href=\"https:\/\/www.star-telegram.com\/profile\/288629615\/\" rel=\"nofollow noopener\" target=\"_blank\">Lillie Davidson<\/a><\/p>\n<p>                    Fort Worth Star-Telegram<\/p>\n<p>            Lillie Davidson is a breaking news reporter for the Fort Worth Star-Telegram. She graduated from TCU in 2025 with a bachelor\u2019s degree in journalism, is fluent in Spanish, and can complete a crossword in five minutes.\n            <\/p>\n","protected":false},"excerpt":{"rendered":"Fort Worth oil heir Sid Bass and his former partner Oona Sperr on a trip to Venice, Italy&hellip;\n","protected":false},"author":2,"featured_media":425736,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[116,118,117],"class_list":["post-425735","post","type-post","status-publish","format-standard","has-post-thumbnail","category-fort-worth","tag-fort-worth","tag-fort-worth-headlines","tag-fort-worth-news"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/posts\/425735","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/comments?post=425735"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/posts\/425735\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/media\/425736"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/media?parent=425735"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/categories?post=425735"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-tx\/wp-json\/wp\/v2\/tags?post=425735"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}