If you were stranded on a deserted island with a member of the opposite sex and this person is married...?

You were on a boat trip in the middle of the Pacific ocean and a freak storm comes along and sinks the boat. All of the passengers except yourself and one married member of the opposite sex were killed. The two of you manage to make it to a deserted island while floating aboard an inflatable raft. Six months go by. Somehow you manage to find shelter, drinkable water and food in order to survive. This extremely attractive married person constantly approaches you asking you to sleep with and they still have a significant other still alive and well out there somewhere. Would you give in or refuse? Even if you don't have access to any type of birth control and it could result in you becoming a mommy or a daddy? What would you do?