a picture/ a message from somebody else

I would ask in curiosity who that person was. I'm not going to DEMAND them to tell me haha. If they say don't worry about it, I would get more curious and keep asking until they either got mad at me or just told me who it was. It's never bad to ask, but just be careful about what you do afterwards with the answer. :) Good luck!

hmmm....i will ask him who the person was and why it was there. if i dont get a good reason i will be mad.

Of course I would tell him! I would first try to find out more information on the subject and I'd carefully plan my move so I catch him unprepared. This type of thing is serious to me and I would certainly confront him and demand an explanation. Of course, I would first check if it's just friendly or that girl is actually his cousin, I wouldn't want to get embarrassed by overacting about something trivial. I once logged in his Facebook account and saw some very disturbing messages. He supposedly had a recurring dream about a girl he'd never met and he tried to find her through Facebook. Of course almost all girls by that name that he approached ignored him but it still felt hurtful to me. It's something he didn't share so it automatically becomes suspicious. It makes me feel bad, not because I'm afraid I might lose him but because I feel he doesn't appreciate me enough. I feel that the slightest attempt to approach other women with flirting methods, is unacceptable unless I am aware of it. I don't ask for a report, I just want to know when such things happen and we could even have fun over them. I sometimes flirt myself and I usually tell him because it seems funny to me. By this, I prove that I have nothing to hide and state my honesty.

If so, I would ask her. Who's on earth the silly guy in the photo? Another question would be, explain me why you keep that? She might tell me a long story abut that. I just wait and listen. And soon after that, I would rush in to my own room. What for? To save some girls photos I keep, lol! No, it is just kidding. If her reason sounds OK to me, then I'll be OK too. But if it sounds irrational, I would tell her that I didn't like what she had done.

We'll talk first, if proven guilty to be cheating on me then it's over. Simple, quick and wise thinking.