The "Watermelon Sugar" singer attended the Brit Awards in London, England, on Tuesday, stepping out to the red carpet in a Gucci suit. Styles wore a black ribbon -- traditionally a symbol of remembrance or mourning -- on his lapel to the event, seemingly in memory of the Love Island UK host who was found dead over the weekend at her London apartment. She was 40.
Styles, 26, briefly dated Flack in 2011 shortly after he gained fame with One Direction on The X Factor. The relationship was seen as controversial at the time, due to their 14-year age gap.
"I still feel 18 and probably act that way half the time," Flack explained in her Storm in a C Cup autobiography. "Although it was just a bit of fun we decided it was best to keep it to ourselves as we were both working for Simon Cowell."
"We were both single, we got on well and we had a laugh," she continued. "It was only when it became public knowledge that things turned sour."
Styles' appearance at the Brit Awards comes just a few days after he was held at knifepoint during a robbery in London. ET has learned that Styles is OK after the scary incident. The incident is an ongoing police investigation.
According to Mirror Online, Styles was robbed at knifepoint on Valentine's Day during a night out in the Hampstead area of London. The British outlet reports that the robber pulled out a knife and demanded cash, and Styles quickly handed it over.
"He actually played it pretty cool, quickly giving the assailant cash, keeping himself and the guy calm and getting the situation over with," a source told Mirror Online. "Understandably though it left him very shaken up afterwards."