Am I being silly?

Hey ladies... Just wanted to get your thoughts on an issue I'm having. I've known my husband 2 years. He is wonderful and treats me well. He has never exhibited any shadiness... Other than last year when I discovered he had downloaded tinder. The app showed up on his Facebook. He apologised profusely and said he was curious and only looked. He was truly sorry and didn't get defensive or angry. Fast forward a year and I went to clean out his gym bag and saw a sex position guide book in there. We have never discussed this book and I didn't know he had it, if it was a book on his shelf or he told me he was going to buy one I wouldn't care, it's just very odd thing to find in his gym bag... Am I being super silly or should I ask him what the hell it is doing in there and why!