Okay Nautilus... you have gone a bit too far. I never meant "if it's something on the side", which implies something hidden. A husband's body belongs to his wife and visa versa. The spouses should know... and I don't mean anything like having to ask permission first or anything weird... just that in there should be open communication in this area. Scripture PLAINLY states the marriage bed is undefiled. I am not condoning an unhealthy scenario... I clearly defined the certain possible application... like if a spouse is unavailable due to distance (like a lengthy bussiness trip, not just working late TONIGHT) or illness (a serious illness). Spouses should always give to each other, since this builds intimacy and strengthens the marriage bond... yet there are scenarios as I have pointed out... that have a positive and practical application.
Regarding the previous post Strong1... saying introduction to masturbation... it is a clinical fact, that very young children and even babies will masturbate... as they can discover certain things "feel good"... it is parents who who generally introduce wrong teaching in this area in an effort to get the uninhibited behavor under control.
I appreciate that this topic has come up... whoever does or doesn't... should check themselves to ensure their reasoning is logical, scriptural, healthy and free of condemnation.