My son likes talking about foreign girls.

Whether it is appropriate or not, the key is that you have to find out the character of this woman and her family. It is better to tear down ten temples than ruin a marriage. You have to be careful about this matter, otherwise the child will lose more than he gains in the future because of this matter. If people behave themselves, just sit and watch. If not, discuss with your son and analyze the possible situation after marriage. Personally, I think it is not easy for a person to find a person he likes among thousands of people.