NO where in Scripture do we find ANY angels; fallen or not; having SEX!
Matthew 22:30
At the resurrection people will neither marry nor be given in marriage; they will be like the angels in heaven.
Since SEX!! is shown; throughout nthe Bible as being permitted ONLY a marriage context; I can only ASSUME (I know...) there will be no SEX! in Heaven.
(NO wonder so many people seem like they want to go to Hell!)