There is no such thing as 'most unusual'.
It depends on the person and on the day of asking. On some days you are more likely to say yes to something a little bit different (within the healthy boundaries of course).
Handling a situation like that has always been easy for me. If i don't feel comfortable with a request i say no to it and wish good luck in finding the right person.
Being straight forward is quite important for me. It saves me the trouble of faking anything!
If it happened shortly after i met up with a gent, I would still say no and ask let him decide if he was happy carrying on or not.