Neurosis, I think you're thinking of Sir William Marshall. Ser Arthur Dayne might owe something to him.
Someone suggested that Margaery's situation at the end of FFC resembles Anne Boleyn's. Anne was accused of witchcraft, incest with her brother George (whose wife gave evidence against them), and adultery with one of her musicians (Mark Smeaton) and four other male courtiers.
Cersei is suspicious of a connection between Margaery and a male musician, and while I haven't seen any reason to think the Tyrell siblings are incestuous, they are quite close. Margaery has been examined and found not to be a virgin--not the same as Anne's problem, but it could lead to trouble.
Margaery's situation reminds me more of Katherine Howard's, Henry VIII's fifth wife (and a cousin of Anne Boleyn's). Katherine, who was, I believe, 16 when she was executed, took as a lover one of her husband's favorite grooms of the chamber, and there was a general impression that she allowed men in the Queen's rooms at inappropriate times. Sounds a bit like the whole Margaery/Pycelle/Moon Tea thing.