Miguel Ángel Parra was supposed to be having a romantic weekend in the town of Cáceres in Extremadura.
Instead, the 27-year-old from Seville ended up seeing his young pet bulldog Homer die after it was thrown from the sixth-floor window of a building in Calle Argentina.
The police version of events has a 24-year-old male friend of Parra's girlfriend banging "insistently" at her door at around 10pm on Saturday night.
Apparently, he wanted to "talk to the young woman," the local police force said.
Police told Spanish newspaper Hoy that the man eventually entered the apartment, picked up Homer and defenestrated him. The man then fled.
Shortly afterwards, national and local police arrived at the scene, as did staff from the local pound, the Refugio San Jorge.
Laura Varaldi, one of their staff spoke about the incident on Monday, saying it was "crazy".
"We hadn't seen anything like it during our whole time at the pound."
She also noted the dog in question was "very well looked after".
The owner, meanwhile, kept asking her: "He's going to be alright, no?" But little Homer had already stopped breathing, said the worker from the pound.
Police didn't take long to capture the puppy's killer, at which point he was brought into a local police station.
"He wasn't just my dog, he was my companion. I had a special affection for him," said a distraught Parra.
"And I'm not just saying it. When I came to see Africa (his girlfriend), there was no question about bringing him.
"He had been with me since he was eight month's old," the dog's owner told Hoy newspaper.
Parra's voice broke up as he spoke, according to the daily.
"They haven't killed my dog. They have killed my friend," he said.
"He was a very friendly animal, very peaceful. He even knew when I was having a bad day," added the young man from Seville.
Parra went on to say he had no intention of dropping the charges against the person who had ended Homer's life.
He said: "This man has to pay for what he did, also because África's mobile phone is full of threats from him,"
Locals in the neighbourhood expressed their shock at the story, although no one had actually witnessed the event.
Under Spanish law, the mistreatment of domestic animals leading to their death is punishable with sentences ranging from three months to a year.
A Madrid court recently sentenced a man to three months in jail for kicking his dog to death in what was described as a "giant step for animal rights" in Spain.
That case is believed to be the first time a Spanish court has been handed a custodial sentence for animal cruelty.