Is it normal to smell your sweaty sack???

Ok, so when I'm out all day especially when it's hot I tend to get sweaty testical's and they normally stick to one of my legs. Anyway I've got this thing where I prise my sack away from which ever leg it's attached itself to, and run my finger down the gap between my ball bag and my leg (it's normally moist) and then take a big deep sniff. Sometimes I take it a step further and share this testicular fragrance with a friend and wipe my finger just above there lips. Some of them get upset, well most of them tell me is this normal?