You need new friends and they are out of their minds!!! If she was naked with another man that means she was having sex with him! Don't be a dimwit on purpose. That is grounds for divorce if you cannot handle this. Yes, you have the right to be concerned. That is what a normal husband would do. Plus are you sure your friends aren't also having sex with her for them to even say that? You better be ready to pack your bags and get out of this. If she cannot explain her self even once, and she gave you a smart answer other than you two aren't having sex frequently. You need to do either two things, either try to work this out through marriage counseling or divorce. She had no reason to be angry at you, unless she held no shame to being an adulterer deliberately.
Are you serious? Or are you another troll? Since you shouldn't really have to ask if you have a right to be concerned. media1.giphy.com/media/l0MYNBYtx4sTQchA4/giphy.gif Her friends will always take her side and be more supportive of her, rather than giving you some advice. Of course you have the right to be angry, what reasonable explanation could she possible have for being naked in bed with another man? Other than she's been having an affair behind your back.
And why will you not have the right? She's your wife. There's nothing wrong being insecure about it; that's obvious. Her friends will support her cause they are her friends. Relationships are based on trust and she needs to be honest with you; if you are not concerned then the chances are possibly that she will cheat you. Good luck.
are you insane,,,,,,, you need to be angry if you found your women naked with another men. your wife gets angry that means that you both don't have a trusted relationship. you both can work on this or say bye to this relationship