Although thousands of miles away from their Bogota home, the couple and their sons Matteo and Marcel found the Church of the Exaltation of the Holy Cross in Kazan, the city where Poland and Colombia meet later on Sunday.
"We are happy to be here, this is a special day for us, it's a kind of historical day for us as a family," said Fabio.
"Of course, for me I would prefer that Colombia win. We will win. Colombia one, Poland zero."
With both countries having lost their opening matches in Group H, another defeat at the Kazan Arena on Sunday could signal the end of the road for their World Cup campaigns.
Teenager Matteo was sporting the bright yellow shirt of his father's country with the younger Marcel dressed in the red of Poland, but they plan to show their neutrality by swapping at halftime.
"It's very difficult but the most important is that one of them needs to win because they start very bad at this World Cup and so (I hope) that the best team wins," Matteo said.
The Perez family were not the only fans from the two predominently catholic countries to wear their colours to mass at the Church of the Exaltation of the Holy Cross on Sunday.
Kazan has always been known as a city of religious harmony in Russia with the population evenly split between the muslim Tatars and christian Russians.
The catholic church is itself a symbol of a religious detente, built a decade ago with the financial assistance of the city government after Pope John Paul II returned the icon of Our Lady of Kazan to the Russian Orthodox Church.
While such significant events were of interest to the Perez family, Sunday was all about something very much more personal.
"We're married for 18 years and today we are here sharing the big moment when our two countries are going to play together," said Isabela.
"Yes, it's crucial match, it's a difficult situation actually."
(Writing by Nick Mulvenney, editing by Ian Chadband)
