Oliver Wilson, 28, of Donington, received a sentence of 34-and-a-half years after being convicted of a string of sexual offences.
His sick partner in crime, Rebecca Holloway, 26, of Rutland Street, Grimsby was sentenced to 13-and-a-half years.
One of the officers involved in the case described the offences as vile and abhorrent and said it was “the most horrendous and emotionally challenging case to work on”.
Officers from Lincolnshire were investigating Wilson, when they discovered a chat log between himself and Holloway.
This chat log described the sexual abuse and rape of a young girl and further sexual abuse of a young boy.
The pair’s evil crimes were uncovered after a joint investigation between Lincolnshire Police and Humberside Police.
The pair both pleaded guilty at Grimsby Crown Court to offences of rape and sexual assault.
In a separate case, Wilson pleaded not guilty to a string of sexual offences on another child, but following a trial last year he was found guilty of 11 further offences for which he was sentenced jointly with the original charges today.
Detective Sergeant Julia Tee-Boon, of the Public Protection Unit at Lincolnshire Police, said: “I would like to say how thankful I am to officers from both Lincolnshire and Humberside for their efforts in what has been without doubt the most horrendous and emotionally challenging case to work on.
"It is their sheer determination and professionalism that has resulted in these offenders both being brought to justice. Crimes such as these are abhorrent and vile, and our forces are fully determined to bringing offenders such as these to justice.
“My thoughts go out to the innocent victims, and we will work hard to make sure all the services are there for them to get all the help and support they need.”
Passing sentence, the judge stated that the text conversations between Wilson and Holloway in which they talk about sexual activity with one of the victims made for some of the most depraved and vile reading he had encountered.