Believe it or not, a HUGE reason why girlfriends end relationships or end up cheating, is because they simply are not sexually satisfied in the bedroom.
And the number one reason why they are not sexually satisfied is because the boyfriend cannot last long enough during sex! Harsh, but true.
Girlfriends get fed up and they move on, while guys often don't know what the heck happened and why the relationship ended or why they were cheated on.
No one wants to admit that it was because of poor sex performance, but often this is the case.
There are many ways this could have been prevented.
The girl could have communicated better to the guy how lousy the sex life is.
If she made this clear, then the guy could have took it more seriously, and most importantly, he could have taken action so that he could last longer in bed.
There are a number of things you can do if you are a guy who needs to last longer in bed:

• Performing exercises that strengthen the ejaculatory muscle.
  
• Breathing techniques to slow down quick ejaculation.
  
• Mental tricks and tactics to avoid anxiety and performance issues.
  
• Creams to numb up the penis and avoid quick ejaculation (not highly recommended, but can be a last resort to quickly save your relationship)

But the absolutely most important thing you can do is the following: Admit to yourself that there is a problem and understand that it WILL have disastrous consequences if you don't take action immediately.
Action should first consist of communication; letting your girlfriend know that you are committed to creating the best sex life possible for the both of you.
Next, you want to take action to improve your lasting ability.
Becoming a long lasting lover in the bedroom could be the best thing you do to improve your relationship and avoid cheating or a break up from occurring.