A Muslim worker in the middle of working in my house one day stopped and asked me if I could give him a room where he could pray. I let him reluctantly but is there any issur for a gentile to pray to his Avodah Zara in one’s home or is it just not proper? TY
While it surely isn’t something that is proper, (the Muslim would never let you do that in his house), still there isn’t any halachic issue with him praying. This is since Islam is not considered real Avodah Zara, as they believe in one God; therefore it isn’t Lifnei Iver to allow him to pray.
Teshuvos Rambam 60.