smell when in use or when not in use?
when not in use. put the pen vape into some sort of airtight tube. I recall being at an ex gf's house and i had it in my jacket (still wearing the jacket at the time) and i could smell a strong scent of chronic coming off me... lucky for me her parents never noticed. she did though and so did I.
for in use I got nothing for ya bud. the peppermint may be a good idea. then you can tell people it's just an e cig instead.