Agree with the 45 mins being far too long, but if it does happen then breath normally!! Holding your breath, which comes naturally to me, only makes things worse ;-) Sent from my iPhone using Tapatalk
A 5min handjob then cum all over their hands.... Great, but a handjob combined with a double whammy blowjob, now that could last 20mins or more!! Just be ready for a big explosion at the end!
It's quite easy actually, all you need to do is make sure they don't rub you too fast, and then just before you're on the verge of coming get them to press on it very hard and hold the grip until you feel the urge stop. After that ask them to take their hands off your dongle for a very short moment about 10 secs or so and then after that they can continue as before using very slow rubbing stimulation. If you want make it less sensitive, put something on it like a rubber, and also make sure they are fully dressed.
Oh yes one other thing I should have mentioned is use a firm but not too hard grip on the penis, with the thumb applying slight pressure at the penis base to. Of course if you think this is a cheating way then just distract your thoughts from the stimulation, and don't think in a sexual way.