"Until Death Though"-- this is Houston slang meaning that what you are saying is fact and you really mean it. You use the term to put emphasis on a statement that has been made by you or another party. 2Death Doe can also be used as a question asking another party to confirm what they have just stated to be true and correct. And an abreviated version "2Death" can also be used as a confirmation of the fact.
If you need me I will be there, 2 Death Doe.
Person 1) I saw him and her come out of the room.
Person 2) 2Death Doe?
Person 1) 2Death.