Is it normal that i wish my wife would lose weight?

My wife used to be very fit and nice looking, and when she had our first kid, she gained some weight but she ate healthy during the pregnancy and she lost most of the weight. Her boobs were enlarged and her hips were widened by the pregnancy and she-looked-STUNNING. We lived a healthy lifestyle and we exercised frequently, and we took our son along with us and we looked great.

But when she had our second kid, she gained more weight and over the years, it has accumulated. She fell away from our healthy and active lifestyle and I am currently still trying to figure out why she has. I am sympathetic to any plight that she may have but even she does not wish to address the issue.

It has been 5 years and she is still slowly accumulating more weight. I don't expect her to be thin, in fact, a few pounds doesn't even register in my mind, but she has gotten straight out fat! I have a hard time becoming sexually aroused by her and I have started taking Viagra. I love her and I love who she is on the inside but my penis doesn't seem to care about personality, shallow as it may sound!

It's worse when she wants me to give her oral sex... Every time I look up, instead of seeing her I see rolls! Seeing her naked does nothing for me, I feel like a young college boy again at one of the frat parties again when the fat girls danced on tables in their underwear and myself and all of my friends go "aauuuuggghhhh get away from me!", but she's my wife!

Whenever I ask my co-workers, they say it is because I am shallow and selfish. If I were shallow and selfish, would I still try to have sex with her, and try to get over my own tendency to think that her physique is just... not... sexually... appealing. I love my wife very much and she is a great person, but she has become very sedentary and after a few years of trying to get into counseling, I am at wits end. Is it normal to wish that my wife would lose some weight and get active again?