Harry Styles' girlfriend Nadine Leopold appeared to have given up after allegedly dumping the One Direction crooner. As per reports, the "You and I" hitmaker has never been dumped before. Te model is reportedly the first girl he liked in a long time, which made the split more difficult.

Here are the alleged reasons behind the Victoria's Secret model's decision:

1. The couple's busy schedules.

According to Heat magazine, Nadine Leopold reasoned out that she's "too busy to date" Harry Styles. Her schedule as a model might have clashed with Styles' commitments to his band. One Direction's "On the Road again Tour" will last until October 31.

2. Harry Styles' alleged infidelity.

While others think that hectic schedules prompted Harry Styles' girlfriend Nadine Leopold to end the romance, a Hollywood Life insider had a different perspective. The source claimed that the model is worried about his faithfulness because he is always "swarmed by gorgeous women."

"Most of the time, it's harmless and he's just being playful, but it definitely affected Nadine," said the same source to the publication. "She was convinced he was cheating while on tour."

The insider added that Nadine Leopold did not have actual proof of Harry Styles' infidelity. Her only evidence is "hearing girls laughing in the background when they talked on the phone or him having his phone turned off for long periods of time."

3. The lack of security.

Another angle being associated with the split is reportedly the relationship's lack of security. As per Hollywood Life, the "Steal My Girl" hitmaker allegedly failed to give Nadine Leopold a "more serious commitment."

"She felt like he needed to make more an effort to see her. She just didn't feel like he was taking their relationship seriously enough, and basically she doesn't have time for any games in her life," said the source.

Prior to Nadine Leopold, Harry Styles dated Caroline Flack, Taylor Swift, Kendall Jenner, and Cara Delevingne.