Okay!

So I don't know why, but it takes me forever to cum, if we're having sex, that's great, but when she's giving me Oral sex, i would like to save her some neck pain

People say have her use her hand, but is spit that good of a lube? cause a few strokes in it gets dry. Most of the time I have to masterbate and have her finish me off. which is not as fun...

and here's something weird: If I have sex missionary poisition, I can literally go on forever, but if we do the "Carnal Clench"
(Girl lies on her stomach, I enter her from behind, kinda like doggy style except shes lying down) I can easily have an orgasm in 5 mins (we use that as the finisher)

I don't know if that information would help, but whatever...