Corceiro and Felix have been dating for three years, but two images have recently circulated online of Porro handing the 19-year-old a shirt after a Sporting game and the pair allegedly seen kissing in a nightclub.
However, Corceiro has denied the allegations, saying that she is "very good friends" with Porro and the situation has gotten "out of control".
Corceiro said: "If I wanted to be kissing someone, in an intimate moment, it would not be in Lust, much less in the VIP area with that little balcony and in view of the entire nightclub.
"I also don't understand why those gentlemen who took the initiative to record that video and report it in such a nice way didn't remember to record me talking and hugging the other people who were there, the other guys, the players, because if we want to talk about Magui Corceiro always with the players and that this is a scene, there was a lot of material."
"It's getting out of control and it's leaving me in a very boring position, and Joao too. I met Porro a few months ago unexpectedly at a group dinner and since then we have had a great time, we are very good friends, I love him, he is incredible and the people who know him know him very well."
Meanwhile, Porro has also commented on the situation, saying that "he has a special relationship" with Corceiro, but that "no-one was being unfaithful".
Felix is yet to respond to the circulating rumours.