There are some techniques that are recommended to help slow things down some. Doing Kegel exercises (do a web search and you'll find info) can help you stop an impending ejaculation. Practicing some stop/start or slow down methods while masturbating can help as well. Mainly though its just about skill in working together with your partner to slow down and enjoy as much as you can. This is something we all deal with so you're not alone.
I practiced with myself to do this, first learn to recognise the exact point when u think you are going to go, then just slow or stop next time you reach it. It also helps if you can control your muscles down there, best way to do this is to try to stop peeing mid flow, then use this same muscle control before you ejaculate. If anything it really heightens sensation!