My boyfriend is the same way I think it's alittle selfish when they act that way ..I feel your pain..
I would have said that I did not want to look for a place for him to get a hair cut. What goes around comes around. Why should you be concerned about what he wants if he is not the same with you.
You should have just gone to look for the stretch mark cream and let him whinge as much as he likes
I think you should have said okay now I need to look for stretch mark cream and when he didn't want to do it, he could sit on those benches at the entrance while you finish shopping.