expression
once over the borders one may do anything; what happens in Vegas, stays in Vegas; shame on a journey can be scratched away
Proverb meaning that when traveling, one can act without worrying about reputation or shame, because strangers won't know you and any embarrassment can be left behind. The literal image is of scratching away shame like dirt.
旅の恥はかき捨てというから、知らない土地では少しくらい羽目を外しても大丈夫だよ。
They say 'once over the borders one may do anything,' so it's okay to let loose a little in a place where nobody knows you.
旅先で派手な服を着るのも、旅の恥はかき捨ての精神だ。
Wearing flashy clothes while traveling is also in the spirit of 'what happens in Vegas, stays in Vegas.'
A traditional Japanese proverb. The literal meaning is 'the shame of a journey is scratched away,' suggesting that embarrassing acts committed while traveling can be easily forgotten or left behind. The exact origin is uncertain, but it reflects the historical reality that travelers were anonymous and free from the usual social constraints.