Salve, Amici.
Here come Cassius Dio, Roman History, Libri LXXI, Cp. II (sec. IV)- III (sec. I):
"Lucius gloried in these exploits and took great pride in them, yet his extreme good fortune did him no good; for he is said to have engaged in a plot later against his father-in‑law Marcus and to have perished by poison before he could carry out any of his plans."
And here comes the Historiae Augustae, Verus, Cp. X, sec. I-IV:
"There was gossip to the effect that he had violated his mother-in‑law Faustina. And it is said that his mother-in‑law killed him treacherously by having poison sprinkled on his oysters, because he had betrayed to the daughter the amour he had had with the mother. However, there arose also that other story related in the Life of Marcus, one utterly inconsistent with the character of such a man. Many, again, fastened the crime of his death upon his wife, since Verus had been too complaisant to Fabia, and her power his wife Lucilla could not endure. Indeed, Lucius and his sister Fabia did become so intimate that gossip went so far as to claim that they had entered into a conspiracy to make away with Marcus, and that when this was betrayed to Marcus by the freedman Agaclytus, Faustina circumvented Lucius in fear that he might circumvent her."
And again (ibid, Cp. XI, sec. II-III)
"There is a well-known story, which Marcus' manner of life will not warrant, that Marcus handed Verus part of a sow's womb which he had poisoned by cutting it with a knife smeared on one side with poison. But it is wrong even to think of such a deed in connection with Marcus, although the plans and deeds of Verus may have well deserved it;"
These are some of the few insights that we can found of an ongoing dynastic conflict when we try to analyze the fabulous, manichean and contradictory history of the "five Good Emperors".
We ought to be extremely critical when approaching these accounts.