Is it just me or does anyone else think sex lasting less than 15 minutes just isn't right? I mean, I don't think I'm in that great a shape, but 45 minutes is ideal for me.
For us it varies, but typically around 30 minutes if it's later at night, closer to 45 minutes if during the afternoon on a lazy weekend (our favourite time), and sometimes much longer if something special has been arranged.
Actual intercourse time's about 10 minutes or so. Thanks to the wonderful Internet, we now have access to many, many stats on sex. One recent Canadian study on intercourse time which was timed by the female partners with stopwatches, came up with an average of 6 minutes. I saw a similar American study that was slightly longer at about 8 minutes, and in my parent's day in the 1950's it was about 2 to 3 minutes. Women have been surveyed, and their ideal duration was 7 to 13 minutes (and 3 minutes was better than 30).
As regards birth control, anyone who relies on condoms needs to re-assess things. When I was younger, no-one used condoms for birth control, because they were too unreliable, and are no more reliable now. I talked this through with my two children when they were teenagers, and both were taught at school to use condoms to prevent sexually transmitted infections, and something more reliable for actual birth control, which is something I always have done. If you are monogamous and STI free, then you can go for natural sex as well.