Religious Conversion

A couple preparing for a religious conversion meets with the orthodox rabbi for their final session. The rabbi asks if they have any final questions.
The man asks, “Is it true that men and women don’t dance together?”
“Yes,” says the rabbi. “For modesty reasons, men and women dance separately.”
“So I can’t dance with my own wife?”
“No.”
“Well, okay,” says the man. “But what about sex?”
“Fine,” says the rabbi. “A mitzvah within the marriage!”
“What about different positions?” the man asks.
“No problem,” says the rabbi.
“Missionary?” the man asks.
“Of course,” replies the rabbi.
“Woman on top?”
“Why not.”
“Well, what about standing up?”
“No!” says the rabbi.
“Why not?” asks the man.
“Could lead to dancing!”