Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever has two wives and inclines towards one of them will come on the Day of Resurrection with one side of his body paralysed."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب القسم والنشوز / 14738