Michelle Critchall was the owner of a male escort agency called "Michelle's Guys" and appeared for multiple episodes in Series 7. Michelle met Jamie Maguire one night at a club and due to the stress of Karen's recent Bipolar disorder worries Jamie cheated on her for the first time. During the sex, Michelle secretly inserted £200 attached to a business card into his pocket and when Jamie discovered it the next day he met with her to return it. Though he told her he wasn't interested when she proposed he start working as a male escort to help the insecure female costumers, he had kept £50 of the money she gave him due to money problems. Preying on the money trouble that had been haunting Jamie and tempting him into rejoining the Maguire family business, Michelle was able to convince him to take the job.
The card from Jamie's pocket.
Against his better judgement and wracked with guilt, Jamie began to have regular paid sex with women just to pay everyday bills. On top of these, Michelle regularly paid Jamie for his "services" herself and became convinced that he loved her. Karen and Paddy soon became suspicious of Jamie's behavior and constant absences however. Karen found a condom in Jamie's pocket and noticed his phone ringing constantly so became convinced he was having an affair, but her own guilt at having an affair with Joe Pritchard and what she put Jamie through with her Bipolar disorder lead to her sadly accepting the situation as him needing to blow off steam. Paddy saw it differently however and began to investigate in order to stop his son making the same mistakes he did and losing his family forever.
Perhaps angered by Jamie answering her insistence he loved her by saying it was all for the money, Michelle circulated cards for he business that featured a picture of Jamie. Jamie found a card and paid Carl Gallagher £50 to help him collect every one they could find and then burn them but involving Carl turned out to be his downfall. Paddy stuck Carl's head into a toilet bowl repeatedly until he admitted what he knew and then booked an appointment with Jamie. He met his son and paid the £200 fee, telling him he should spend the time with his family because once they were gone he would never get them back but Jamie replied by punching him.
Despite his insistence that his father should mind his own business, Jamie followed his advice and quit the job as one of "Michelle's Guys". Michelle reacted by threatening to tell Karen everything but she soon stopped when Jamie insisted he was going to tell her himself. Jamie did attempt to confess to Karen but she began to get manic and shout that she didn't "want to hear it", even turning on the stereo to cover Jamie's words before running out of the room. Michelle later turned up at The Jockey, she requested a word with the landlady but Jamie assured her Karen knew everything. Michelle accepted this but admitted that him quitting had left her a man short and though there was plenty of men willing to take his place, there was no one "qualified".
Jamie later took Carl to Michelle's pent house apartment where he "auditioned" for the job by stripping naked. Michelle was happily shocked by the size of his penis and happily hired him as Jamie's replacement. They had rampant sex over and over until Michelle ran out of money to pay for it but Carl spotted her stereo and jewelry box and assured her they could work something out.
Jamie later apologized to Karen for his recent behavior, Karen asked if he was leaving her but he assured her that he wasn't. He lied and told her that all the recent late nights and phone calls had just been business and now it was over, Karen happily replied that business goes straight over her head so she didn't need to hear more.
Later, when Karen's affair with Joe Pritchard was discovered Jamie admitted cheating himself though he never went into detail. He was never seen on screen mentioning his brief escort career to Karen, so it is likely the drama of her affair lead to it being forgotten.