ok... but seriously .... too long also quite sianz right....
one reason could be :
1) you pcc a lot. You are used to getting the feeling or sensation that comes from the preassure that you are able to control by using the hand so much that the expanding and contracting preassure from vagina power have no more effect on you.
2) don't smoke too much, better still don't smoke or drink. it's science that these two vices prohibit sexsual gratification, but you can have them after you shoot.

it's relaxing to smoke after you shoot. But I prefer not now, becasue hard to cum again

3) sad but true, your KKJ too small for her hole, vice versa, her hole too big for you KKJ. Type = Mis-match
In this case, you can ask her to switch to hand and fondle your balls at the same time.
One sure "almost" sure case is to ask her to use her palm to touch the tip of your dick gently while she use the other hand to shake. Ask her not to grap too tightly, or else no blood= KKJ die. No good.

this method often used when in the car.
4) If she blow you using her mouth and you cannot cum, oh boy ... it's not your fault if you didn't take vices before hand and didn't PPC 24hrs before. Just tell her, she's just not good enough

. Different girls dare to try different pattern, some girl daring but still conservative.
Alternative : asked her switch to hands as above (3)
Hope these helps....enjoy your sex life
