There is a rumor out there that Mel Brooks converted to Catholicism upon marrying Anne Bancroft.
There is also a rumor out there that Anne Bancroft converted to Judaism upon marrying Mel Brooks.
As far as we can tell, both of those rumors are just that, rumors. The two compromised: he stayed Jewish, she stayed Catholic.
Although, as with many compromises, there are some complications. When son Max was born, Anne wanted to have him baptized. Mel didn't, so another compromise was reached: Max would be baptized, but also bar mitzvahed when he turned 13.
And then, when Max became an adult, what religion did he end up choosing?
Judaism.
Sometimes these things just work themselves out, don't they?