The double amputee is accused of murdering the South African model, whom he shot dead through a bathroom door at his home in Pretoria on Valentine's Day last year.
On day two of his testimony, Pistorius revealed that he was "besotted" with Steenkamp shortly after the pair met at the Sports Awards in November 2012.
The 27-year-old read out to the High Court one of the messages from Steenkamp, which said: "I'm scared of you sometimes and how u snap at me and of how you will react to me. You make me happy 90% of the time and I think we are amazing together but I am not some other bitch you may know trying to kill your vibe."
Pistorius also read out a number of loving text messages, in which both referred to each other as "special" on occasion.
The athlete denies murder by maintaining that he mistook Steenkamp for an intruder when he fired the gunshots.