Wacky Dr. Who Theory!
A Time Lord's sexual orientation can change with each regeneration.
Their default orientation is asexual- possibly purposely engineered to keep the population down. For beings that can live hundreds of years, over-population could become a significant problem. However, every once in a while, after a regeneration they pop up as non-asexual. Ten is hetero, so is Eight, and we can presume One as well, since he had to get that granddaughter somehow. Eleven, I think, is gay- he does seem to go on a bit about how good looking Jeff is. This explains, for instance, how Five traveled with so many attractive companions of both genders without a hint of temptation. Also, why Nine didn't show any romantic interest in Rose, but when he became Ten, he fell in love with her.
I just posted this on the Wild Mass Guessing page over at Tv Tropes: http://tvtropes.org/pmwiki/pmwiki.php/WMG/DoctorWhoWithSpoilers
Their default orientation is asexual- possibly purposely engineered to keep the population down. For beings that can live hundreds of years, over-population could become a significant problem. However, every once in a while, after a regeneration they pop up as non-asexual. Ten is hetero, so is Eight, and we can presume One as well, since he had to get that granddaughter somehow. Eleven, I think, is gay- he does seem to go on a bit about how good looking Jeff is. This explains, for instance, how Five traveled with so many attractive companions of both genders without a hint of temptation. Also, why Nine didn't show any romantic interest in Rose, but when he became Ten, he fell in love with her.
I just posted this on the Wild Mass Guessing page over at Tv Tropes: http://tvtropes.org/pmwiki/pmwiki.php/WMG/DoctorWhoWithSpoilers