Its a scenario played out with couples every day. Girl buys and outfit,or tries it on in a shop and turns to her partner and says "what do you think?"
So do the ladies expect honesty? do you really actually care what he thinks when you like it yourself?
And if he said he hated it would you not buy it? or do you expect him to just go through the ritual of saying how lovely it is?
I reckon the majority of guys just say anything for the sake of peace tbh.