Well, not in my Bible either, maybe in the Gospel of FC?
if Mary didn't have sex with Joseph she sinned and her children were by some other man.
So did she have sex with her husband as the Bible says (and you catholics insist is not true) or were her children by someone other than her husband?
Also, the Bible says that married couples do not with hold sex from one another.
So if Mary did not have sex, she sinned.
James 4:17 Therefore to him that knoweth to do good, and doeth it not, to him it is sin.