Is it wrong to play Mah Jong in a Catholic woman’s house? There is also another Jew there beside myself at the game. The Catholic woman says she believes that Judaism and Catholicism have many of the same beliefs. I disagree with that but have not addressed it with her. She has two daughters-in-law who are Jews. One converted to Catholicism and one didn’t.
There are two issues here. The first one, is if there will be a yichud issue, but that will depend on the individual circumstances. The second, and more probable one is if this is the correct situation for you to put yourself into. When you socialize with such people, you are apt to learn ideas, and other things that can have a negative effect on you. This can happen even if it is only from casual conversation. A person’s life view comes out, the person’s mannerisms, preferences, and many other things about them that can be different to torah and can have a negative effect on us. For example, if she will casually say something positive about her avoda zara, that statement has an effect on us, now you might choose not to react to it, and not say anything in order not to make a fight, but the affect is still there inside of you. This is, in part, why Chazal prohibited bishul akum, and pas akum, because our socializing with them can have a negative effect on us.