The Moon Is Blue is a delightful 1953 film about seduction, based on a German play translated in 1951 to English and staged on Broadway.
It begins with a day game out-shopping pickup. Donald Gresham (played by William Holden, who has a habit of playing the moody seducer types) receives an approach invitation from Patty O'Neill (played by the charming Maggie McNamara), but fails to approach after she backturns him and walks away.
When he spots her eying him a second time a few moments later, he realizes she's definitely into him and he'd better chase her down to make his approach. So chase her down he does.
This entire film is about pickup, seduction, and male and female dynamics. The words 'pick up', 'seduce', and 'seducer' appear throughout its runtime.
If you like film examples of seductions, or you're interested in seduction dynamics, you're almost certain to like this film.