If it's the same thing as I get, it's not a sore. The top and inside of my lip become swollen and rough and tender. Chapstik (or equivalent) helps. Eating butter or icecream or anything fatty (to dissolve the offending compound) helps. It doesn't honestly last all that long unless you insist to keep smoking, in which case it can turn into a cold-sore like thing except it heals MUCH faster and easier and doesn't spread at all.
If you are like me...
If you take a pipe of something REALLY mild, it won't happen at all.
If you take a pipe of something REALLY strong (e.g. 1792 flake), it gets MUCH worse and happens sooner.
Smoking slower only helps until you're about 2/3 through the bowl, and then it hits anyway.
Smoking faster will burn your tongue instead, which feels different, but your lips will be fine.
If condensation from the pipes comes out to your lips, not only does it taste really bad but the effect happens instantly and severely.
Smoking a cigar without a holder is a guarantee.
Smoking a cigar with a holder is good until the last two inches or so, and then it happens even if you use pipe cleaners and paper towels to dry up the condensation.
If that sounds like you, I feel you.