I am hesitant to be intimate with my wife?

I hope not to offend anyone with my question regarding my wife's toys, so please do not read on if this would bother anyone. This is a follow up to an earlier question. My wife has indicated that I satisfy her when I am with her. She does also use a vibrator on herself when she feels it is necessary, about 2-3 times a week. I do not question her right to do this. However, I recently jokingly asked her to estimate my size, and she said she thinks I am below average (though in truth I am average). I do not know why she said this and she could not explain her statement either. Also, she purchased a new toy this week that is fairly large (bigger than me). I have been hesitant to be intimate with her for about a week now. How do I get over this feeling? Am I just being insecure?