The breaking of the glass in a Jewish ceremony means that the bond between the two people shall never break.
Judaism looks at sex in a very positive way seeing it as the very essence of marriage. The purity laws are very important to having a good sexual relationship. The laws allow for two weeks of physical intimacy, then two weeks of abstinence. This helps rebuild a couple's desire for one another.
Birth control (but not condoms) is allowed in Judaism if the couple already has a boy and a girl, or if the mother has mental stress, or physical problems. Condoms are seen as an artifical barrier in trying to achieve intimacy.

