楼主,我非常理解你的心情。依你所要,在这里我们只谈科学,不谈伦理、爱情与婚姻。你的这个问题其实很复杂,可以说在科学界一直争论不休。这个一个遗传生物学方面的问题。我不是科学家,无法给你一个确切的答案。不过,一些研究表明这种担心并不是空穴来风。前几年轰动全球的一本科普读物《精子的战争》里面紧密地涉及到你所关心的这个问题。这本书是遗传生物学家Dr. Robin Baker所著;在全球范围都十分轰动!摘录一下这本书英文原版介绍的一段话:If you've ever looked upon sperm as a little army of white-coated soldiers setting off to sack and pillage a barely pregnable fortress . . . well, you'd be right, according to this fascinating new book. Dr. Robin Baker, who has studied sperm and cervical mucus in much greater detail than anyone would've thought necessary, has come to some startling conclusions: that less than 1 percent of sperm is actually designed to fertilize an egg (the rest are there to block other men's sperm), and that 4 to 10 percent of all children born to married couples are in fact the offspring of other men, usually of higher socioeconomic status, with whom the mother had a short-term relationship.另外,“zhuliyu1982”所贴这段话的描述恐怕并非是完全杜撰出来的。在临床医学上曾发生过这种尴尬的事情,在一本医学杂志上刊登过。它不是绝对地发生,而是一定机率的发生。本人以前在国外读心理学的并从事过一些研究。西方心理学大量涉及遗传基因等问题。从一个进化心理学的研究角度,我想造成处女情节真正的根源恐怕是生物遗传方面的因素。西方人虽然没什么处女情节,但你要看到他们的高离婚率、高比例的同居不婚状态以及淡漠的亲子关系。恐怕这些现象与此因素也很难脱离关系。补充说明:摘录的这段英文没有错。这是国外网上书店对该书的介绍。而引用的也是作者的研究结果。然而,需要注意的是这段话是对该书的介绍,而不是解释“zhuliyu1982”所说的那段话。也许先前没说清,我只是建议你看看这本书,可能有你要的答案。你说的精子存活期约为5天没错,但那只代表精子在此时段后失去活性或者说受精的可能性。这个问题你最好请教遗传生物学方面的专家。