Joe Giudice Opens Up About Teresa's Life in Prison

— -- "Real Housewives of New Jersey" star Joe Giudice is opening up about life without his wife Teresa, who is serving a 15-month prison sentence at Danbury Federal Prison.

Giudice spoke to "Extra" and said his four daughters -- Gia, 13, Milania 9, Gabriella, 8, and Audriana, 3 -- keep in touch with their mom almost everyday.

“They email her all the time ... every day, so, they email more than me," he told the show.

He also spoke about raising his girls without their mother.

"You have to stay strong, when you have four kids, you have to stay strong," he said. “Her being away definitely makes me appreciate her way more, a lot more, and you know everything she did."

In the interview premiering today in full, Giudice, 42, who also has an upcoming prison sentence of 3 1/2 years for fraud after Teresa gets out, added that behind bars, his wife has "a little group she hangs out with and does her thing with every day, and who she goes to the gym with and who she hangs out with, and who does her hair and who does her nails. They have their little thing going every day.”

In fact, he said the family -- who goes up to see Teresa every weekend -- once wait an hour for her while she was doing her hair.

Also, in another interview with US Weekly, Joe said after he leaves from visiting his wife, also 42, in prison, "I cry more than the girls. I pretty much cry every time I leave. Like a little baby."