As an old-fashioned type of man, I often do little things like opening doors for ladies as a sign of courtesy. Of course, sometimes the women would show their appreciation with a simple “thank you”.
What if the person who did the good deed is not an English speaker?
http://is2.okcupid.com/users/112/26/11302762098146592552/p1122791055.jpg
Get yourself a Chinese courtesy phrase tattooed on your leg. Problem solved.
多謝 means "many thanks".
Perhaps her other leg says “come again”.