I sometimes sniff and lick my friend in his sleep
You must be joking. Why do you sniff and lick your friend?
I do that to taste his young manly sweat.
You shouldn't do things to people who are sleeping. This is without consent and you can go to jail for it.
I'll never get caught.
Even if you're never caught, sniffing and licking your friend without his consent is a terrible thing to do, and you should stop. It's a clear violation of boundaries, and super inappropriate.