I am always confused when people state that it is against nature to have or desire sex. The last time I checked those desires are quite natural. Then there is the belief that sex w/o the possibility of children is wrong (because Odin spilled his seed and was killed). Well Odin disobayed the ritual of providing his brothers wife children. If I was to attempt to impregnate my brothers wife because he passed away I think the Church might have a problem with it.
As Cathoics we believe Mary was able to concieve with out ever experiencing any sex. If God wanted my wife to get pregnant I do not think any form of contraception would prevent it.
IF we are to believe the early writtings of the church I would not be considered married because I treated my wife as a Harlot when I lusted for her and had intercourse for the pleasure of it. I believe God gave us a beautiful gift in all the forms of sexuality and with that gift we need to be careful my own desires should not over shadow my wife’s. It should be a mutual form of passion in which we become even closer. :