just a pic

I've been with my man for about 2 years. and I completely trust him... Well yesterday he went out with our roommate (male) and our R/M old work friend (female). Our R/M boat just got fixed so he wanted to go. Anyways, on my computer bf has his Google account that has all his Google photos and we had just went on a trip like 4 days ago, so I went on to get the photos, and tell me WHY my bf took like 3 candid type photos of the chick that went boating with them yesterday... I am beyond pissed ...like am I just over reacting? Why should he take a picture of any female thats not family or of me???