<human>: Give me a shortened version of the text

I've been with my boyfriend for a little over a year. In the past, I was slightly worried at times that he wasn't being completely honest with me about little things. He said that he doesn't tell me things that might upset me when I told him I want him to be 100% honest with me. I'm not sure if this means a random girl hitting on him or something worse.

When we were first starting to date, I found a necklace and lipstick on his nightstand. When this was brought up, he said that he found them below his bed while cleaning, and must have been left by the previous occupants of the house (it was rented out and the bed frame and dresser were left in the house). I believed him and let it go, but should I have?

 He also has a passcode on his phone. I have talked to him about this and refuses to budge, saying that the passcode is to keep his son out of his phone, or for just in case his phone gets stolen. I know it's reasonable, smart even, to have a passcode on your phone, but I can't help but think that he is hiding something from me. If he is texting on his phone he always has it at an angle so that it's out of my view. 

I met him through a friend, who does not approve of him, which is a huge concern. She has known him for a long time, but she also has a tendency to be dramatic, exaggerate, and was cheated on in a long term relationship. When I talked to her about my concerns, she says they are red flags. 

I don't know if she is biased from her past relationship or if I am rightly suspicious. When I talked to him about how I was feeling it turned into an argument. He says his ex-girlfriend was crazy, had major insecurity issues, and was convinced he was cheating on her. I'm thinking maybe she was like that because of behavior of his similar to what I'm experiencing. I've never been in a long-term relationship previously, so I'm not sure if it's reasonable to be worried.
<bot>: My good friend does not like my boyfriend, he is secretive about his phone, I once found a necklace on his nightstand, says his ex was crazy and paranoid that he was cheating.