Michael and Roberta were in correspondence between approximately 1949 and 1951. Only Michael’s side of the correspondence has survived, having been given by Roberta to her biographer and friend Liz Hodgkinson. It is not known what became of Roberta’s letters to Michael, but given the way in which their relationship ended he may have destroyed them. 
 
Roberta first became aware of Michael by reading his book Self: a Study in Ethics and Endocrinology, and got in touch via his publisher. He was initially hesitant about her request for a meeting, as his only previous meeting with a reader had turned out to be a gay man who asked him for the names of other homosexuals in London. However, he was immediately enamoured by Roberta at their first meeting, and told her about his transition only an hour after meeting her. His subsequent letters develop from friendly to romantic.
 
As Roberta’s letters to Michael have not survived, her own feelings about the relationship are unknown. She later denied that she had ever had any feelings for him, and said that she would have considered a marriage between them ‘two females getting married’. From Michael’s letters, however, it is obvious that he believed they were in a romantic relationship, and that she gave him reasons to believe this. She sent him photos of herself to display in his flat and show off to friends, and was introduced to his aunts in Folkestone as his prospective future wife. He wrote frequently about potential wedding arrangements, such as hymn selections and possible venues, and about collecting furniture and other things for their future home, and even about the possibility of having children together. (Roberta’s two existing children from her previous marriage are never mentioned.)
 
The obstacle to their marriage was Roberta’s legal status, as she was still legally considered male, and in order to remedy this she would need surgery. An orchiectomy - removal of the teste s- was a necessary step for Roberta to be able to obtain a female birth certificate, and thus for them to be able to marry. Because of an archaic law known as mayhem law (definition here), it was illegal for a surgeon to remove healthy testicles. Michael’s own surgeon, Dr Harold Gillies, was unwilling to operate on Roberta, as by doing so he risked losing his license and potential criminal charges. 
 
Faced with this double-bind, a drastic solution had to be found. A handwritten document testifies to the agreement they eventually reached - that Michael, a fourth year medical student, would perform the operation himself. In the document, which is clearly intended to protect Michael from legal consequences if Roberta died during the operation, she gave her consent to the procedure in the full knowledge that he was still a medical student and had never performed it before. One of his later letters quotes a line from the hymn ‘Father, hear the prayer we offer’, which he apparently recited while performing the operation, and which he said he wanted played at their wedding:
 
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‘Be our strength in hours of weakness, in our wanderings be our guide, in endeavour, failure, danger, Father be thou at our side'
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Michael performed the surgery on the kitchen table of Alison Macbeth, a doctor who had helped both of them with their respective transitions. Despite his lack of qualifications or experience, the operation was successful. Roberta was able to obtain a female birth certificate in May 1951, eliminating the legal obstacle to their marriage. He sent Roberta an engagement ring in a cigarette package, and told her to wait to open it until after he had passed his final exams, although by this point he already considered them to be engaged and wrote to his family and friends to inform them. 
 
Michael passed his final exams and became Dr Laurence Michael Dillon in July 1951. The collection of his letters to Roberta ends after about April 1951 (many of them are undated), so how exactly their relationship ended is unknown. His friend Gilbert Barrow asked what had happened with the relationship and was told ‘It’s all over’.
 
Neither Michael nor Roberta acknowledged their relationship in their respective autobiographies. Michael never mentions Roberta at all, while Roberta briefly describes their first meeting but does not name Michael or mention any further relationship.