Dog doesnt seem to like my wife

Question
About 7 months ago, my wife and I (~50) rescued a Bichon mix (3.5 yrs, 20 lbs.)  She is a very sweet dog, mellow, well behaved.  Our dog is very loving, but will come to me like I'm the best thing ever, and treats my wife like yesterday's mail.  If the two of them are alone together , she will follow my wife around and treats her like a queen.  Another point...If there are ANY guests (male of female) in our home, our dog will go to them and flop over for belly rub over my wife.  This is starting to hurt my wife's feelings.  My wife feeds our dog  about 60% of the time.  She makes her sit and down etc. many times each day for treats etc.  Our dog takes commands from both me and my wife equally and there are no defiance issues.  What is going on???  What can we do??

Answer
This is generally out of curiosity,and dogs are social and want to say 'hi' to new people. Something that can curb this is to tell guests to ignore the dog for at least ten minutes and have your wife pet the dog in between those times,and even give her a treat. This isn't so much the dog disliking your wife,as it is about looking for attention and saying 'hi' from new people,but if they ignore her and she will learn they aren't going to give her attention but your wife will-she will stay closer to your wife