How do I bring this up to my boyfriend

I had my boyfriend's phone yesterday and I was trying to search something on his Google and in his search history he had Googled suicide hotline... I went through his call history to see if he had called that number because I have no idea why he would even Google that and he had.... Idk what to say. Trying to act like I didn't see anything was hard. I've been acting normal but I want to bring this up. Just not sure how.