The court was told Emmanuel Gardiner took advantage of single mother Stephanie Tranmer so he could use her home as cover to hide his criminality.
Tramner’s barrister, Ian Hudson, said Gardiner and Tranmer had met each other through social media.
He said Tranmer had been single and vulnerable as a result of previous abusive relationships.
Mr Hudson said Tranmer’s home provided Gardiner with the opportunity to store drugs and weapons as police would not suspect that illegal activity would be going on at her home.
Mr Hudson said: “They never went out together as a couple.
“She was someone who had low self-esteem. He would come to her house and never met the children.
“She believed she was lucky to be in a relationship with him.
“She thought he was a good boyfriend just because he wasn’t violent to her and did not raise his voice.”
Mr Hudson said Tranmer had no previous convictions.
He urged judge Mushtaq Khkhar to take the ‘exceptional course’ of suspending a prison sentence in Tranmer’s case despite firearms offences usually carrying a minimum five-year custodial sentence.
Michael Devlin, for Gardiner, said his client had been in prison on remand since July last year. Since that time two women - neither of whom were Tranmer - had given birth to children he had fathered.
Mr Devlin said: “He wishes to express his remorse through me. He knows he is going to receive a significant prison sentence.”
After the case, Detective Inspector Phil Jackson, of Leeds District Serious Organised Crime Unit, said: “Gardiner was someone heavily involved in the organised supply of Class A drugs, which do enormous damage in our communities.
“As part of his criminal trade he had possession of firearms which had the potential to kill or cause significant harm. The criminal use of guns and ammunition on the streets is an issue that understandably causes the public real concern. I hope the significant sentence Gardiner has received will send a very clear message to those involved in their use or possession of the penalties they can expect.”