100% agree. I felt so sorry for Sandra when reading those messages. She kept pretending that somehow this was a normal relationship that would somehow have a happy ending even though that murdering creep told her over and over it wasn’t going to happen. Her persistence with the threats of exposure while also looking forward to him coming to her baby shower etc.. etc..made me think that she had no concept of what love in a relationship looks like - due in large part I’m sure to the grooming and abuse she received.
You know, lots of things might be simply explained by SB having no father figure in her life, perhaps? And then, if she worshipped the police, it added to it. In some families, the police showed up as the "saviors", maybe this is where it came from. So, first a girl who is in awe of LE, then a policeman who is her mentor, and MF could have been viewed as a young father by her. And then, he became Sandra's first man. Add to it that SB’s relatives die, and MF was probably the only stable figure in her life.
Why did she want to have a child? Well, this is why I suspect she was a vulnerable adult. However, didn’t MF and SB become lovers before he got married? I am just thinking out loud, MOO, If, if! - MF explained to SB that he had to marry because his wife to be was expecting, then in the mind of a naive 15-year-old girl, the idea that “men marry because women get pregnant”, could have lodged itself. And perhaps while her goal to get pregnant was because she wanted MF to marry her, MF was thinking, “if I give her a child, she’d let me go.” Plus, maybe, he thought that him having an identical twin brother would make it hard to prove whose child it was.
Anyhow, these are just ideas. Surely the fact that under the guise of Police Explorers these very adult men were engaged in something that smells of a pedophile circus, is horrible.