As a Buddhist of over 30 years, I found the Trimondi book to be absurd.
I read that the Trimondis were financed by the German Communist Party to
write an anti-Buddhist propaganda book against the Dalai Lama. I also
read that the Trimondis are two German Communists with suspected links
to the Bader-Meinhoff terrorist organization. Stick with respected and
trusted Buddhist authors.
Edit: Well, you seem to have stumbled on a land mine with the Trimondi
book. Probably any other link is better than that one. One mistake
Trimondi makes is to take that which is a metaphor, visualization, or is
to be imagined as literal. This is one of the main reasons that the
tantras are not taught to beginners. One thing to keep in mind is that
one of the fundamental tenets of Buddhism is to not harm others. So
anything you've read that seems to indicate the contrary is probably a
metaphor for something else, such as defeating one's ego-centeredness
rather than an actual physical enemy.
As for Buddhism and sex. There's no such thing as a tantric orgy. If you
heard of such a thing happening, it's just purely indulgence in a
regular worldly orgy.
And you should know that yes, Buddhists have sex. Otherwise we'd have
died off a long time ago. It's monks who generally don't have sex,
except that a very few Tibetan monks have wives. The point of abstaining
from sex for a monk is to simplify their lives so they can practice the
dharma. If there are sexual feelings, they are acknowledged and worked
with just like any other thought. As with any emotion, passion is
suffering when it has the aspect of attachment. Also, Buddhists do not
partake of sex in a way that harms others.
New Tibetan Buddhist students should be taught Buddhism in a gradual
manner, beginning with the fundamentals of Hinayana and Mahayana, and
lastly, after probably years of study, begin to study the tantras,
which, as I have said, are quite susceptible to misinterpretation,
particularly for non-Buddhists and people new to Buddhism.
BTW, I think you will never read what I have added because you don't
allow contacts or emails, so I can't draw your attention to it, but if
you actually do check back here, you may email me if you would like to
continue this discussion.
http://tinyurl.com/9ra3kyv