Alexander, I've been alive for hundreds of years. I've been with men, been with women -
with faeries and warlocks and vampires, and even a djinn or two. ”
–Magnus to Alec
Over a century later in The Mortal Instruments, he becomes romantically involved with Alec
Lightwood, being the boy's first kiss and relationship. Magnus says in The Infernal Devices that
black hair and blue eyes are his favorite combination, which only Alec and Will Herondale are
shown to have.
The issue of his immortality versus Alec's mortality is brought up several times in City of Fallen
Angels, when Camille, Magnus's ex-girlfriend/lover, says that in sixty or seventy years, Alec will
eventually age and die while Magnus will continue to live on forever. This in which, causes
heavy complications in the two's relationship. However, it is revealed in City of Lost Souls that
Magnus had been seriously considering taking away his immortality, confessing that while he is
immortal, all he has wanted was to find someone he loved to live the rest of his life and to
grow old with and had hoped and wanted for it to be with Alec.
In The Infernal Devices , he is the lover of Lady Camille Belcourt. However, they break up after
Magnus discovers that Camille has gone to St. Petersburg to be with a human lover.