Swift has had several high-profile romances over the years, including with actor Tom Hiddleston (36) and DJ Calvin Harris (33).
The couple, who have been together since May, have rarely been spotted together but a source says that they are very much in love.
'It's very normal, and no one really knows about it right now. They are still taking it slow'.
The song is third song released off "Reputation.' It follows 'Look What You Made Me Do" and 'Ready For It'.More news: Aaron Rodgers sends out positive message following surgery
'Her decision to keep her relationship with Joe quiet is making her happy, ' said the insider.
Whenever she releases a new song or album, Swifties thrive on speculating which ex-boyfriend she's condemning or celebrity ( Katy Perry cough cough) she's dissing.
Look What You Made Me Do became the most viewed music video within 24 hours - breaking Psy's record - and became the fastest song by a female artist to reach number one on USA iTunes.
Lines such as "Ocean blue eyes looking in mine/I feel like I might sink and drown and die" (Alwyn has blue eyes) and "You should take it as a compliment".
She previously dated Calvin from March 2015 to June 2016 and Tom from June to August 2016.