I hear people talking about how it is faux pas to wear shorts with long-sleeve tops. This is not true. Almost as true as the rule being not be able to wear white after Labor day. Who ever made that rule is sick; if you can't wear white after Labor day, than when are you going to be able to wear it?
Just know guys that "fashion rules" are most of the time just other peoples opinion. There is no right or wrong way to express your individuality through fashion. So yes, now that it is getting warm outside, if you feel you would like to rock a sweater with some cargos - go right ahead. Tell the haters to back down.