What do you expect, here You are, still having sex with your wife, probably letting the dog, especially when he was younger, sleep in the bedroom, or whatever! Now you take that sexual organ away from this poor guy - continue on with your sex life, he's pissed-off at you Buddy!! and he knows if he hits on your wife's possessions, she will get angry at You - tit for tat!! Animals are really intelligent, check it out with a reputable "dog whisper".. no joke! Until such time, give your "best friend" something of hers and let him keep it and don't get up-set with him. He is Only a child still! Good Luck and if he keeps it up - check to see if he is getting more teeth, give him a "frozen" facecloth, dogs love to chew on it. Keep a few handy in the freezer - try it out.