If you are not married you have no need and no business reading such a book. If you are married, you will enrich your love life together much more by working on mutual communication, self-giving and intimacy so that you arrive at expressions of love satisfying and fulfilling for both of you. How lame and unromantic to seek that knowledge from an outsider.
Since the pictures inevitably will intrude in the intimate life of third parties, you have no business looking at them and it is doubtful most people could read such a book without finding it a definite occassion of sin.
Calls to mind some male friends of mine who in college (we were so innocent in those days) were induced to send away for such a book advertised in one of their magazines (Playboy in those days was on a par with the average teen fashion or celebritay mag nowdays). It promised full color illustrations. It delivered on its promise in that the illustrations were stick figures, blue for the girl, red for the guy. They socked up $20 for it.