Just because they speak Portuguese doesn't mean they don't speak Spanish as well. They are somewhat similar languages after all, most Brazilians I've met in the States speak both.
You're not wrong. I'm born in Brazil and found it very easy to learn spanish after already speaking portuguese. Its harder the other way around for some reason though apparently. It would be interesting to hear that group speaking to eachother given how mixed the languages and dialects must be (Lucas from south brazil, Coutinho from Rio, Suarez from uruguay, a couple of spaniards, a frenchman, Teixeira from portugal, etc). They must really have some sort of warped fucked up linguistic mix going
