There is nothing banning me marrying the local oak tree. Where do we draw the line?

Sripture clearly sets out the marriage covenant. Male/male is simply not part of it.

I am very sympathetic to your need CSL, but unlike masturbation, there are other Scriptures which show that male/male pairing was wrong in certain circumstances, perhaps the principles that underlie these extend into marriage as well.

Blessings
Cat.