[Northern]

Depends on what excuse you gave to go ktvs.
Meet friends la kopi, work late ? cig smell from friends/nearby table, chatting time colleague smoking.

Perfume smell, avoid girls with strong perfume.

Excuse, friend bring gf, really strong perfume, lady colleague really strong perfume.

Then legit excuse to ktv

Boss bring to ktv, friend sad, friend happy, friend want to try ktv, friend birthday.

Also, you have to be more specific, explain to who in particular ?
wife/gf/parents/siblings/relative ?
If every time go ktv need to explain to so many ppl, then you have bigger problems than evidence of ktv.

Each circumstances precautions different.