Los Angeles, Dec 8 (IANS): Actor Joe Alwyn, who is dating singer Taylor Swift, likes to keep his relationship as private as possible.

Alwyn says there is "a very clear line" for him of how much he should share about his relationship with Swift, reported usmagazine.com

"I know what I feel about it. I think there's a very clear line as to what somebody should share, or feel like they have to share, and what they don't want to and shouldn't have to," he said in an interview to Esquire magazine.

The "I knew you were trouble" hitmaker and the "Mary, Queen Of Scots" star have been dating for over a year and a half.

A source told the publication that Swift is "the happiest she's ever been" with Alwyn.

"Joe has really showed her a different lifestyle and the value of privacy. He's very supportive of her career. Taylor is so much happier without her personal life in the open. She credits Joe for that and realizes how much better off she is," the source reported.