Neil Simon looks at what it takes to be a successful sinner.

Life is full of those nagging “what-ifs?”

They seem to jump out at you the older you get. What if I would’ve taken a different career path? What if I would’ve went with a different guy or gal, or neither? What if I would’ve followed my heart instead of common sense?

They’re all questions you’ve got to deal with at some point, in one way or another. Usually it comes down to a decision of either abandoning the idea altogether, chalking it up as a memory of what could have been, or diving in head first to find exactly what if … .

This is where we find Barney Cashman, the main character of the Jewel Box Theater’s season finale —  “The Last of the Red Hot Lovers” by Neil Simon —  which debuts July 18 in Poulsbo.

Cashman (played by David Siskin) is described as a nebbish, middle-aged man who married his high school sweetheart once upon a time and has led a fairly straight and subdued life ever since. As the years tranquilly pass by, Cashman is anxious for excitement and aching to join the sexual revolution before it’s too late. He longs for the insubordinate thrill of an extra-marital affair. The only problem is, he’s a gentle soul with absolutely no experience in sin.

A tell-tale sign — Cashman attempts to seduce his menagerie of sexual partners at his mother’s apartment.

On three afternoons (which make up the play’s three acts) Cashman brings a different girl back to his mom’s house while she’s away at work. Each affair reveals how unsuccessful he is in the business of sin.

First he strikes out with a cigarette-smoking sexpot with a taste for whiskey and other women’s husbands. His second attempt, with an actress friend, is spoiled when he discovers just how crazy actresses can be. So in desperation he asks up the only other woman he think of: His wife’s best friend, Thelma.

Tell-tale sign of a non-sinner No. 2 — never attempt to cheat on your wife with her best friend.

Perhaps that’s a large part of the message in this piece.

In his hilarious yet thought-provoking style, the playwright Simon sets the stage with comedy and quips and yet again delivers the wisdom on human nature in this 1969 comedy.

Neil Simon’s “The Last of the Red Hot Lovers”premieres at 8 p.m. July 18 at the Jewel Box, 225 Iverson St. in Poulsbo. The show will run through Aug. 16 with curtains at 8 p.m. Fridays and Saturdays and two matinees at 2 p.m. Aug. 3 and 10. Tickets are $12-14. Info: www.jewelboxpoulsbo.org or call (360) 779-9688.