Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: The Messenger of Allah (peace and blessings be upon him) said: "A woman is not to be married in addition to her paternal aunt (i.e. while her paternal aunt is in the man's marriage), nor in addition to her maternal aunt."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11755