Husband's facebook (UPDATE)

So my husband left his facebook open and went to the washroom and I couldn't resist the urge to check his messages. I know, bad move. He was talking to this female friend he has and she was going on about how it is hard for her to type now because she has long nails and she jokingly said she can scare her SO with them now. And my husband replied she can use them for other things too instead of just scaring - winky face at the end. I know he meant back scratching during sex because he loves that. I was so mad when I read that. To have female friends is one thing but discussing such things is another. Am I overreacting or did he overstep the boundaries? (UPDATE) He is just mad that I checked his facebook. Sent me a youtube video about not spying on your spouse. I know I didn't do the greatest thing in the world by checking his messages but that's all he has to say??