Some men have problems with this their entire life, doesn't matter how experienced they become. Other suggestions have been that you masterbate prior earlier in the day when you're going to have sex so that the urgency is not there. There are also creams out there to make you less sensitive. Use them with a condom however (also helps delay things) so it does not transfer to her and make her less sensitive. If you think a surrogate will help, what's the harm in using it?

It is much better in a long term relationship. I don't understand the whole casual sexual relationship thing, I've never heard of the sex being good in these situations.