Re: How would you react…
No I am not … See if initially he had been so caring , and knew that his girl wouldn’t not like him doing what he did - he wouldn’t have done it .
Secondly - now as he has done it - then what’s the point telling the girl - who think of him so high ! indeed you desi girl think that their SO are some angel - No most of us men are not … we do fall prey so such weak moments . err is bloody human .
Now from Girl’s point of view - she should consider the way - the story was told :
if told out of guilty with a promise of not doing it again - Then she should move on … but if it was told to check out the reaction and leveling the ground for future endeavors - Then it is alarming .
may be - by telling this to her , he is trying to know margin he could get out it for future / marking the boundaries for future acts .
I have said it many times darlings 
… to win our hearts - your lot need to think like a desi woman and act like a western man or may be vice versa for few odd couples 