Guys turn into spineless morons once they have GF (me excluded)

This is the story of Aryan , one of my very good friends.. Aryan, I , krish and nisha were known as the family in IITD, coz of our propensity to always hang out together. Then came smita , the home wrecker.
Some background is necessary for this story.
Aryan keeps falling in love (not quite unlike me ). He falls in love at the slightest pretext , or so it seems to me. I have known 5 girls that he has been in love with. Thankfully (or not) he is marrying the fifth.
The first one was pratiksha, her father got her married off to some guy in the US. End of story. I am pretty sure she also was in love with Aryan, but ……..
Second one was a bitch in our class. He refuses to accept that he was in love with her but I have corroboration from a lot of people that he was. That thing never went ahead beyond friendship .
Third one was a girl he met at some quiz contest. He once shopped for a gift for the girl with me , for reasons he never told me. I think , in fact a lot of people think that he proposed to her and she refused , but dont have clinching evidence to prove the same.
Fourth one is really interesting, I am the only one who knows about it. No one else on this earth knows about it. He did not quite tell the girl how he felt but assumed that she refused (twisted , isn’t it ??)
Now comes the interesting part. After the supposed refusal by the mystery gal , he meets pratiksha. He knew that se was senti about him and asked us how he could refuse her politely. So I thought that he is past it. I remember me sitting with him and some other ppl and discussing as to what wud be the best way to say no to her. We assumed he is safely beyond the machinations of this female.
Then one night wen I was sitting with nisha at Nescafe , he says to us “I am getting married to pratiksha “
We were too stunned to say anything , but like the true friends we were , we took him to comesum at nizamuddin and extracted a treat out if him.
For the life of me I cant understand how he went from “how can I refuse her in the nicest possible manner “to “I am getting married to her “
But the worst part was yet to come. This female systematically tore him apart from us( or so I believe). He used to spend 25hrs in day with us , now he wud never be seen . I got lot of heartburn about it.
Perhaps this is how it happens,. I agree that he has to spend rest of his life with her , but we were also his friends. I think I have cribbed enough about this.
But he question is , do all guys turn into spineless idiots after they fall (whtever) in love with a girl ?
More important thing is , will this happen to me as well??