Taylor Swift said that Justin Bieber and Selena Gomez's reunion as a couple is the "worst possible thing," a source told MSN News, leaving many wondering if she will enter into a feud with the "Heartbreaker" singer over her.

 "Taylor is being extra protective of Selena. She thinks Selena reuniting with Bieber is the worst possible thing," the source told the site.

"Selena had been staying at Taylor's home for rest and relaxation, but the two had a blow-up after Selena admitting to being in secret contact with Bieber since before Christmas."

Selena Gomez and Justin Bieber recently went out on a Segway date in Calabasas, Calif. on Thursday and her best friend Taylor Swift may not be too happy about it.

"Once Taylor finds out that Selena is hanging out with Justin she will be very mad," a source told HollywoodLife.com.

"This is exactly what Selena has told Taylor all along that she would not do, and now that she has, [it] will show Taylor that she can't trust Selena."

But her friendship with Selena Gomez isn't the only thing fans are buzzing about.

Taylor Swift was rejected by Douglas Booth when making requests to spend New Year's Eve together, HollywoodLife.com reports, leaving many fans wondering if he's giving her the cold shoulder because he found out she dated him to get ex-boyfriend Harry Styles jealous.

A source told the website Taylor Swift went on a date with Douglas Booth in November with the purpose of getting back at her ex-boyfriend.

"Taylor's date with Douglas was all about making Harry jealous, and she made sure that everyone found out about her night out," the source said, according to the site.

"Taylor usually tries to be really low-profile, but for her meeting with Douglas she purposely chose somewhere that she knew would get attention. She went to one of busiest pubs in London and sat in the public area. She wanted the news to get out about the date because she knows it will make Harry jealous."

The 24-year-old celebrity allegedly came on "too strong" to Douglas Booth and continued to badger him with date requests even after giving her signals that he was not interested.

Taylor Swift, however, claims the two are just friends and that even mentioned that she "never chases boys" when rumors about her relationship with Douglas Booth surfaced.

No information has been revealed regarding her future interactions with the "Romeo And Juliet" star.