This is a tough one because I can understand why it would set off little alarms in your head. Some people really are super protective of their phone and the things on it that they consider personal. I have been married for 14 years and my husband is private with the information on his phone, he feels it is his phone so it is none of my business what may be on it. I on the other hand am very open with who I am texting or calling.

Maybe it is worth trying to talk to your boyfriend about this, maybe try explaining that it just kind of caught you off guard and that you wouldn't want to snoop through his phone. Perhaps he has a reasonable reason to keep the information private.