Britney Spears gyrated in lingerie following news of her dad’s widely-reported health horror. The ‘Toxic’ singer, 42, was seen in an Instagram video posted on Tuesday (05.12.23) dressed in a pink lacy dress dancing to Peggy Lee’s 1958 hit ‘Fever’ hours after sources said her dad Jamie Spears, 71, had his leg amputated. Despite the shock headlines, Britney – who was held under a controversial conservatorship controlled by her dad for 13 years – swayed her hips and whipped her blonde hair while also dressed in burgundy high heels. She captioned the post: “Filmed this last night but my dress was …