The 24-year-old beauty and the `Written in the Stars` hitmaker have reportedly been secretly dating and Jessie has told friends she is in love.
A source told LOOK magazine: "Jessie`s smitten. She`s saying, `I can`t believe it`s happened to me but I`ve really fallen for him` and it`s like they were meant to be together. She`s totally changed. It`s as if she has finally found someone she can relate to and trust."
Jessie and Tinie, 23 are said to have enjoyed a number of low-key dates because they want their romance to remain under wraps for now.
The source added: "They`d go out for walks in the evenings, both pulling up their hoodies so nobody saw them and then they`d just hang out in the park or local cafes. They`ve just been doing normal things."
The pair - who performed together at the Royal Albert Hall last year in aid of the Teenage Cancer Trust - first became close when Jessie asked Tinie for advice during filming for the UK version of `The Voice` - which sees her on the panel alongside Sir Tom Jones, will.i.am and Danny O`Donoghue.
The insider explained: "Tinie talked her through a few pointers to get her on-screen performance up to scratch. Then he invited her over to his place to hang out and that`s when the sparks between them started to fly."