A stalker threatened to kill his ex-girlfriend's mum and make her perform a sex act on him in a bid to force her to reveal her daughter's location.
Domitru Stoian's partner was moved to a safe house when their relationship ended after allegations of violence.
Unable to contact her directly Stoian, of Nash Close in Corby, launched a stalking campaign against her mum which was so terrifying she too had to move house.
On Thursday (August 5) at Northampton Magistrates' Court the 40-year-old was locked up.
Magistrates heard the stalker started contacting his victim on June 4, sending obscene messages about her and her daughter.
Prosecutor Stella Moses said: "He referred to them as whores. He said 'I am going to smash your door down and kill you'."
Further vile messages followed before, the next day, he sent a message saying: "Please, I ask you nicely to tell me where she is."
The victim did not respond and Stoian, who appeared at court over videolink from HMP Peterborough, went on to send more horrifying messages.
One chilling threat said: "When you come out I am going to **** you."
And another said he was going to make her and her daughter perform a sex act on him.
A total of 13 more messages were sent that day, the court heard.
The victim contacted police and when they arrived and were speaking to her Stoian called again.
This time he said he was aware police were looking for him and said he would go to 'the refuge' - wrongly believing his ex-partner was in a women's refuge in Cambridge - and smash the windows.
And another message sent by the stalker said: "If I find out it was you you should move out of Corby by tonight."
Stoian later pleaded guilty to stalking through a course of conduct which threatened violence, rape and sex acts, threatened to kill her, ordered her to leave town and sent unwanted text messages.
A statement read by Ms Moses on behalf of the victim said she was in the process of moving house to somewhere safe.
Ms Moses said: "As a result she says she is in fear for her life and her safety.
"She said 'I feel like I am in danger all of the time and he stops me from living my life'."
Stoian, who has no previous convictions, gave no comment answers when interviewed by police.
He was unpresented in court and was given the opportunity to address magistrates, which he used to question the victim's statements and claim his ex-partner keeps in touch through his extended family.
He claimed she had said that she wanted them to get back together when he is released from prison.
The court heard Stoian's offences had a punishment range of between a community order and 26 weeks in prison.
Chair of the bench Susan Sharrock jailed the stalker for a total of 10 weeks.
She said: "We consider this to be a serious offence.
"Your conduct was intended to cause a high level of fear with threats of violence and resulted in very serious distress to the victim, who has made changes to her lifestyle as a result."
Stoian was ordered to pay compensation of £200, costs of £85 and a surcharge to fund victim services of £128
A restraining order was made banning contact with his ex-partner's mother for five years.