WASHINGTON — I spend a lot of time coaching people about money management. Without a doubt, the saddest sessions — the ones that draw the most tears — are when people are fighting with family about finances.

The combat can get particularly nasty when it involves siblings, who seem to know just the right insults to hurt deeply.

And can I be honest? Many of these arguments are the result of parents stoking rivalries or playing favorites, particularly to irresponsible adult children. Or a parent will tell one child one thing and another something entirely different. Sometimes it’s to keep the peace among warring adult children, but other times it’s a conscious act to deceive.

I’ve opened up an avenue for readers to ask my opinion about family financial feuds. In this regular feature, I try to step back and provide some clarity of how I see the situation. Sometimes it helps to get an outsider’s viewpoint. Recently I heard from a reader who is upset about parental support that a sibling is receiving.

The background: The reader’s sister, who is 30, has received substantial financial assistance from the parents her entire adult life. They were paying her rent at one time, and now she lives in their basement. The woman’s unemployed boyfriend is also staying there and has been for about nine months — including during a period when they were broken up. The reader feels alone among her family in being upset about how the parents have supported the sister.

The battle: “Not to get into any emotional issues,’’ the reader said, “I want to know why I am the only one [in the family] to find a problem with [the boyfriend] living off of my parents as well. Even when they broke up, he moved to a different room but still paid no rent and had no job. No, actually he’d got a job but had to quit after a week because he thought construction work was too hard. My parents think they’re helping someone who is down on his luck. They also paid to get his car fixed and all his insurance and gas money. Why am I the only one who doesn’t trust him?’’

The bottom line: I’d like to unwrap this as best I can without additional information. (People don’t always give me all the facts.)

Let’s start with the rent. A lot of young adults have trouble making ends meet. They may be underemployed, carrying student loan debt or both. So I’m not opposed to parents chipping in to help an adult child starting out.

But parents have to distinguish between help and a handout to someone who isn’t trying his or her best to be independent. I’m particularly concerned about parents who are retired and digging into limited retirement funds to help an irresponsible adult stay that way.

You are doing your child a disservice — and, really, you aren’t being a good parent when you enable poor behavior. If the spigot is never turned off, it will run dry. Then what? How have you helped your child learn to survive on his or her own?

Regarding the reader’s sister moving back in with her folks, I’m not opposed to that either. My husband and I have told our children they are welcome to return home after college to save and prepare themselves to live on their own. In fact, we encourage it. Our older daughter is about to graduate from college (Yeah!) and she’s going straight to graduate school. We’ve told her that after she finishes her education, she should come home. We want her to save the money she would pay for rent for a few years so that once she launches she’ll have a fully funded emergency pot or even money for a down payment on a home of her own.

And I’ll add this: I’m a fan of multigenerational or shared housing. In many high-cost areas, it’s hard for families to afford rent or a house. Shared living space is one solution to this problem.

Now as to the boyfriend: It wouldn’t happen if it were my house. The parents are not responsible for supporting this grown man, who is not married to their daughter — and who appears to have no work ethic. Please.

Finally, as for my reader, I understand the concern. Who wants to see their parents taking care of a trifling adult child? But, in this case, if the parents are being taken advantage of, it’s by their choice.

And if this is about the sister getting more than she deserves, let it go. It’s not your money.

Michelle Singletary can be reached at michelle.singletary@washpost.com Follow her on Twitter @SingletaryM.