snowbird....Okay, thanks for the publication info, that confirms that the particular book you have is a translation of the haggadaic Hebrew text published in 1625. That text, although late, is a valuable piece of Jewish midrash that adds to our knowledge of Jewish interpretation of the Torah, and may well contain traditions that originated in the Second Temple period. I've posted about its nativity account of Abraham (ch. 8) which bears striking resemblance to Christian nativity traditions of Jesus and the parallel Jewish nativity account of Moses (Sefer ha-Zikronot 38b), and the question of whether the Abraham legend is based on the Christian story or whether it preserves older haggadaic traditions that the Christian story is itself dependent on. It is also interesting to compare it with other similar midrashim, like the Genesis Apocryphon, Pseudo-Philo, Jubilees, Genesis Rabbah, and of course the Talmud (Haggadah).
The Book of the Watchers reports that 200 angels descended on Mt Hermon during the days of Jared and changed themselves into human form. They then copulated with women and produced the Nephilim. Was this rape or was it consensual? The Bible states that they took wives for themselves - all whom they wanted. Multiple wives, perhaps? Whatever the case, my take is that the women had little say in the matter. How could they be blamed?
If such a thing really happened, then we could talk about the issue of consent but these are fictional characters within a sexist story, so the story is going to criticize them on grounds that you and I do not recognize as being at all valid. The story doesn't care about their point of view, their choice in the matter, or them at all as people. They are simply necessary props to the author's characterization of the fallen angels as evil sinners; they are only the occasion for the sinful actions of the antagonists. Of course, reality shines a bright light into the artificial constructedness of such a story.
BTW, there are lots of literary tidbits here behind the scenes. Jared in Hebrew comes from a root meaning "descend", so the author writes that the angels descended during the days of Jared. A nice little piece of midrash there. The story also claims that the angels bound themselves by a curse when they gathered on Mount Hermon; this is another pun on the name of the mountain (from herem "curse"). The story is filled with similar word plays.
One other interesting detail is that the story claims that the angels gave mankind many technological and cultural inventions which lead inevitably to sin. This updates a much older myth (familiar from Ugarit, Phoenicia, Babylonia, even Greek mythology) that the gods bequeathed on man many of the inventions we use, e.g. fishing, city building, agriculture, wine, etc. But the inventions that the angels gave are all negative ones. Making weapons for war. Sorcery and astrology. Making witches' brews. But guess what one of them is? Cosmetics. Evidently, the angels liked their human wives to be made up with blush and eye shadow. The use of such cosmetics would thus imply that the women were complicit in the sin that corrupted the earth. It would have made them more alluring to the angels. Interestingly, the early church father Tertullian wrote a whole treatise against women's fashion and cosmetics called De Cultu Feminarum and he extensively cites 1 Enoch as proof that cosmetics are the work of the Devil.