Up front let me say this is my personal opinion – with support as I will mention.
I think that God intended us to have intercourse as often as possible. Not just sex, but penis in vagina intercourse. It’s well documented that intercourse affects our bodies and minds in ways no other sex act does.
- Intercourse results in a greater release of oxytocin (the touch, bonding hormone) than any other sex act. Oxytocin causes us to feel closer, and makes sex more enjoyable.
- More intercourse results in more testosterone in women. That may result in a better sex drive. 1
- Intercourse results in greater prolactin release than other sex acts (four times more than masturbation for example). As prolactin is what makes us feel sated, this may indicate that intercourse is more satisfying. This may also mean that intercourse causes us to feel sexually satisfied for a longer period of time. (Many men find that masturbation does not reduce their sex drive as much or as long as intercourse, and that manual or oral sex by their wife is somewhere between the two). 2
- After intercourse, men and women respond better to stress than they do after other sex acts – and the effect lasts for days. 3
- Vaginal exposure to semen may reduce the risk of breast cancer. The study I’ve cited is ancient. I’ve seen references to a French study done in 1985 which showed the same thing. I’ve also seen mention of a clinical review in 1995 that hypothesized that oxytocin and DHEA that result from orgasm may reduce the incidence of breast cancer. I’ve seen similar claims for cervical cancer, citing a study also from the late 70’s, but have not tracked down the study. (Note: this is NOT the same as the fake story that swallowing semen reduces breast cancer.) 4
- “[Intercourse] frequency, rather than other sexual activities, is associated with sexual satisfaction, health, and well-being.” 5
Most couples feel closer, more connected after intercourse than any other sex act. So, while all sex is good, intercourse is the better for a couple’s relationship than other sex acts. That being the case, I see all other sex acts as options when a couple can’t have intercourse or when they are having a great deal of intercourse and want to play a bit. Regularly excluding intercourse seems to be cheating a couple out of some of the things sex can, and in my mind should, contribute to their marriage.
Let me be clear I am not saying it’s wrong to climax in other ways, or that we should never climax in other ways. My point is that we benefit more from intercourse than other sex acts, and need to have a good deal of intercourse to get all that God intended us to get. If I had to put a number on it, I’d say intercourse three times a week is needed for most of the benefit. So, if you have sex more often than that, doing something else should not be an issue if you manage intercourse three times most weeks. On the other hand, if you have sex less often than three times a week, excluding intercourse for any other sex act seems a bad plan if intercourse is possible.