How gay and straight men and women view SEX

These generalizations are complements of the text book referenced below.  The author's present them in regards to research that I have not personally reviewed.  That being said, the information comes with a credible backdrop, makes sense intuitively and is quite interesting.  So as I will be teaching next week....-

Heterosexual men can separate sex from love relatively easily however, they report better sex with women to whom they do have an emotional attachment.
Gay men are also able to separate love from sex and in fact have the most casual sex of the four groups listed here (makes sense - they do not have to contend with those emotional women!)
Heterosexual women are not as inclined to separate love from sex and less likely to have casual sex.  However, I wonder if this is a societal construct more than a "woman" difference. Heterosexual women have their self esteem tied to their involvement in "committed" relationships.
Lesbian women have more of an emotional and physical intimacy with their partner.  They initiate sex later in the relationships (regardless of what the L Word shows!) and have sex less often.  They have more touching, caressing and similar intimacies.

In addition to these groups are celibate persons who choose not to "do it" at all and may be more productive individuals because of this abstinence and asexual persons who feel no attraction to either sex.  I wonder if celibacy can lead one to become asexual.  Asexuals do continue to have sex in spite of their lack of attraction (according to the text) where as the celibate have the attraction and not the sex!

Human Sexuality: Diversity in Contemporary America by William Yarber, Barbara Sayad, Bryan Strong - McGraw-Hill Higher Education (2009)