The Jewish father warned his son against marrying a shiksa [non-Jewish woman]. The son replied,
“But she’s converting to Judaism.”
“It doesn’t matter,” the old man said. “A shiksa will cause problems.”

After the wedding, the father called the son, who was in business with him, and asked him why he was not at work.
“It’s Shabbat,” the son replied.
The father was surprised: “But we always work on Saturday. It’s our busiest day.”
“I won’t work anymore on Saturday,” the son insisted, “because my wife wants us to go to shul on Shabbat.”
“See,” the father says. “I told you marrying a shiksa would cause problems.”