Interesting thread. After years of cajoling, begging and trying to use logic, my wife finally got to a mindset that allowed her to blow me. It's been about 25 years now. She always let's me cum in her mouth but never swallows - no big loss for me. The funny thing is that she has zero interest in cunnilingus. I've pushed and have been able to go down on her no more than ten times over the years, exactly one time to orgasm. (Before anyone jumps to the obvious conclusion, she insists it has nothing to do with my skill level; she just isn't comfortable with my face in her privates.)
Blow jobs are my favorite but creeping anorgasmia and penile insensitivity make it very difficult for me to cum. This is very disheartening. Not guaranteed, but easier in a pussy. To give you an idea of her transformation and what a trooper she is, after a failed blow job, she will encourage me to stroke one off and she'll jump in to take the cum in her mouth. 30 years ago, I couldn't have dreamed it.
Lately, she has become much more open to letting me manually bring her to orgasm (used to be off limits) so I'm hoping to again broach the option of oral on her. I think it would alleviate my anorgasmia if I could get her to cum by licking her pussy.