The 29-year-old Scream Queens star had dated model Matthew Paetz for nearly two years before calling time on their relationship earlier this month.
According to Entertainment Tonight a source revealed that Lea's newly single status was unexpected as no-one saw the split coming, they called the break-up a "huge shock to all their friends."
The insider added that Lea and Matthew had been discussing getting engaged "as recently as around the holidays," which made their decision all the more surprising to those close to them.
The Glee actress first met Matthew back in April 2014 while filming her music video for 'On My Way.'
Romance blossomed quickly between the pair and things soon turned serious, with Matt moving in with Lea four months after they started dating.
Her relationship with Matthew was Lea's first since the death of her Glee co-star and boyfriend Cory Monteith, who passed away in July 2013.
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