Taylor Swift
Taylor Swift and Calvin Harris at the Billboard Music Awards 2015 – they have been together for four monthsBillboard

Taylor Swift is already head-over-heels in love with Calvin Harris and she wants the world to know. The Daily Mail reports that the Shake It Off hitmaker stunned concertgoers during the finale show of her 1989 tour by declaring her love for her boyfriend, as he watched on in the crowd.

According to fans, after belting out her last song of the night, Shake It Off, the 25-year-old popstar took her final bows and then mouthed the words "I love you" to the 31-year-old Scottish DJ.

For her final performance the Bad Blood hitmaker made sure to go out with a bang with another riveting show and special celebrity guests that included Natalie Maines of the Dixie Chicks, Ellen DeGeneres and Alanis Morissette. She slipped into a sparkly pink-fringed number featuring a tiny top and matching miniskirt with glittery peep-toe booties for the final song and could be seen dancing to the beat as the crowd cheered.

Swift and Harris have been dating since February when they met at the Brit awards. The couple made their relationship public when Swift kissed Harris during the Billboard Music Awards 2015, held at the MGM Grand Arena in Las Vegas on 17 May.

In July, the power couple beat Beyonce Knowles and Jay Z to become Forbes magazine's highest-paid celebrity couple of 2015. The lovebirds took the top spot with combined earnings of $146m (£94m) over the past 12 months.

Earlier in August, she denied rumours that she was moving to Scotland after it was reported that she was eyeing up a £4.6million 16th-century castle north of Perth. The property boasts eight bedrooms and seven bathrooms in the main house and dates back to 1570. Its also features two gate lodges and two staff cottages – along with an 18-hole golf course, tennis courts and heated swimming pool.

She quickly set the record straight on Twitter telling fans: "Cause baby I could build a castle out of all the bricks they threw at me" – a line from New Romantics. But I'm not actually buying a castle."