Gary Crompton bombarded Anne Gardner with love letters, repeatedly went to her Standish home and even followed her, Wigan Magistrates' Court heard.
Crompton, 44, of Clap Gate Lane, Goose Green, admitted harassing Miss Gardner between September 11 and December 6.

Katie McFarlane, prosecuting, said Crompton, who works as a scaffolder, began his adulterous affair with Miss Gardner after meeting her while carrying out some work on her house in July 2005.
Miss McFarlane said: "They started going out but after about six months she began to have doubts about whether he was still with his wife.
"After questioning him she ended the relationship.
"He then went over the top, bombarding her with letters, phones calls and flowers.
"She gave in and started going out with him again."

Miss McFarlane said Crompton and his mistress again spilt up on New Year's Eve 2006 after he promised to spend the evening with her, but instead spent it with his wife.
Miss McFarlane said: "She told him it was over, but he kept getting his mother to speak to her and bombarded her with letters and text messages again.
"He started to follow her and her daughter was afraid as he would bang on the door at all hours and push notes through."

Last year Crompton was diagnosed with cancer and in August had to have reconstructive surgery in London.
Miss McFarlane said because of this his estranged mistress "decided to be there for him."
But when they had an argument in September and he smashed her mobile phone, she finished with him again.

Between September and December he pushed love letters through her door, called at her house, followed her to her home and left a birthday cake on her doorstep.
She called police on November 15 and Crompton was warned about his behaviour.
However, the harassment continued.

Kevin Liston, defending, said Miss Gardner said: "He fully accepts he should have walked away, but he was being passed messages from her friends who said she still loved him, so foolishly he thought it was worth fighting for.
"Through the course of the relationship he has paid her household bills, her car insurance and for her to have driving lessons and wonders whether that caused her to keep stringing him along.

"He has been going through a traumatic time in his life – he has had a serious illness, reconstructive surgery, is going through a divorce, has issues with access to his children and on top of the mental turmoil of his illness he has been trying to work out what has been happening with his relationship."

Crompton received a 12-month conditional discharge and was made the subject of a restraining order banning him from contacting Miss Gardner or from going within 100m of her Standish home or her workplace in Parbold.
He was also ordered to pay £43 court costs.