I have a rather odd question I was hoping I could find an answer here regarding sensitivity, or lasting time. I'm 21 and have been with the same girl for over 4 years now (married in fact) and we've noticed something a bit odd from time to time regarding my ability to stay. We've been unable to find anything that might be causing it and thought somebody else might have an idea.
I normally last, during intercourse, for 10-15 minutes or so; which is great for us both. However, at times I have trouble lasting more than a couple of minutes. The odd part is, it isn't for just a day. It normally last a week or two and then its back to normal for a couple of months. My wife is lucky enough to orgasm through intercourse and she has a hard time reaching climax during this period and it is very frustrating for both of us; when most of the time it isn't uncommon for her climax more than once per "session".
Any ideas on what causes this or any way to overcome it? Anywhere else I might find an answer?