Their first encounter in New York at New Year's eve when they kissed was memorable to both of them. It just Ash didn't realize it was Karlyle when they met again. It was actually their first kissed made him realize (Ash) that he could be with an Alpha. He actually went back to the same spot to see if he could meet Karlyle again after new year but to no avail. So yeah let's just say it was fate that they met again.
The part explained these three relationship wasn’t adapted so: Ash used to have a crush on Nick before he met Karlyle, Karlyle doesn’t like Nick because he thought Nick had broken his brother (Kyle)’s heart many times and he believed he’s not a good partner to his brother. While hanging out with Nick (Nick had no interest in Ash), Ash met Karlyle again while Ash and Nick were about to hug each other, and Karlyle misunderstood that Nick was having an affair behind Kyle’s back. Because of that, he said some harsh words to Nick and Ash couldn’t stand seeing his crush being insulted by such an arrogant man so that’s why he said he didn’t like him when they “first met” (atp he still didn’t recognize Karlyle’s the alpha he kissed 6 years ago)
I don't get it like why didn't ash like Lyle in-the beginning bc it was never specified what hapened between lyle Nicholas and ash idk