This is a modern day internet mockup overly used by teenagers, and some nerds. It implies a slight tongue in cheek remark relating to a persons own sexuality whilst at the same time mis-spelling the word ''the'' and changing it to ''teh''.
When first looked upon, it may look as though a person is stating abuot themselves that they are:
When infact they are just showing their ability to laugh at themselves and act in a ''homo-erotic'' manner of somesort. It is widely used across message boards and whatnot.
Mullan: Im taller than you so I win.......
Dave: But I am teh ghey sexy