Taylor Swift
Taylor Swift and Calvin Harris are spending quality time together ahead of her world tourREUTERS/L.E. Baskow

American singer/songwriter Taylor Swift and Scottish singer/DJ Calvin Harris are reportedly getting serious about their relationship.

According to E! News, the 31-year-old I Need Your Love singer and the 25-year-old Shake It Off singer "are spending every free day they have together" before she travels the world for her 1989 tour.

"Whenever she has a break in her tour, she flies on her private jet to meet up with him," the source revealed.

"Taylor feels very safe and secure with Calvin so she usually doesn't have her bodyguard around if Calvin is over," the insider added. "Sometimes she will leave for a few hours and go on a hike with friends or go to a business meeting, but they always meet up again later in the day."

"She is planning on having Calvin join her in certain cities and also will be bringing him to her beach house in Rhode Island."

Rumours that Rita Ora's former boyfriend and Swift are dating started in March, and the two were pictured shopping in Nashville, dressed similarly.

Later, the two were spotted at a Kenny Chesney concert, getting cosy in the audience.

It was previously revealed that Swift has been single since splitting up with One Direction singer Harry Styles, after the pair dated for a whirlwind two months in 2014.