Laura Keane (RASHIDA JONES) is a nearly forty-year-old writer who's married to successful businessman Dean (MARLON WAYANS), but due to carrying most of the weight of raising their two younger daughters her career has been put on hold.

She also wonders if her romance with Dean has diminished, what with him working so many hours and heading off on business trips with his attractive project manager, Fiona (JESSICA HENWICK). Worried about that, she confides in her father, Felix (BILL MURRAY), which probably isn't a good idea as he -- speaking from personal experience -- is fairly certain Dean is cheating on her.

With the resources and connections to play amateur detective, he eventually has Laura starting to think the same, and soon both set out to follow Dean and discover whether that's true or not.

Everyone knows the old saying that you can't teach an old dog new tricks. In essence, that means the older someone is, and the longer they've been doing things a certain way, there's no sense in trying to change that or them. It reminds me of when New York Giants quarterback Eli Manning was instructed a few years back to change the way he positioned his feet before any shotgun snap, essentially making him relearn something he had been doing the same way for decades.

It didn't work and the coaches should have simply let him do his thing with better support from others, what with him having been a two-time Super Bowl MVP. The same goes for plenty of veterans in any variety of professions, including Hollywood actors. That thought came to mind while watching "On the Rocks" where it's all too clear that writer/director Sofia Coppola is simply letting Bill Murray do this thing and be, well, Bill Murray.

In this dramedy that reunites the two -- following 2003's "Lost in Translation" and the 2015 Netflix film "A Very Murray Christmas' -- the comedy legend plays Felix, an aging but still eager to charm bachelor playboy who's contacted by his nearly forty-year-old daughter, Laura (Rashida Jones).

She's concerned that the spark is gone and the flame turned down a lot in her marriage to her husband, Dean (Marlon Wayans). That's left her feeling like a harried housewife who does nothing but raise their young girls with nary any time to resurrect her now-dormant writing career, all while he's out building his ever-growing business and spending more and more time traveling with his pretty account manager, Fiona (Jessica Fenwick).

That causes dear old dad -- speaking from years of experience he doesn't deny -- to assure her that in the old "men will be men with wandering eyes, hands and loins" mantra that her hubby is probably cheating on her. And thus he sets out, with her as his somewhat unwilling and uncomfortable detective partner, to catch Dean in the act.

While plenty of moms who put their careers on hold to raise one or more kids will likely identify and empathize with the stay at home protagonist, there really isn't much in the way of story -- beyond the default settings -- to sustain interest in Jones' character, particularly with the material played fairly lightly.

Instead, the focus falls more on Murray's character whenever he shows up -- which is fairly often -- and does typical Bill Murray things such as singing to a bunch of strangers he's just met at a Mexican resort's bar and so on. You can't deny he's a charming codger -- the real-life man and the character he plays -- and that quality helps carry this otherwise very lightweight caper wannabe flick.

All of which means Coppola was wise to let the veteran actor simply do his thing rather than directing him to act another way. Only they know how much was scripted and how much was improvised, but Murray's fans probably won't care as they'll likely enjoy what he offers that helps boost what's otherwise a mediocre offering. "On the Rocks" rates as a 5 out of 10.