Q: I have a problem with my fiance’s ex. They have a child together. She always calls him just to talk about their 6-year-old son and then starts chit-chatting about stuff that has nothing to do with their son.

She also expects my fiance to be at all their son’s sports games even though she has moved out of town and has a boyfriend and a baby of her own.

How can I approach this subject with my fiance without straining our relationship? I wish she would leave us alone and give us custody of the little guy. It’s getting so I am starting to resent the poor kid and I love him as if he were one of my own, but she does get in the way of our weekends sometimes.

A: There are red flags waving all over at your house. It sounds to us like you think she’s wrong — and we aren’t so sure she is. The chatting about stuff that has nothing to do with their son? That boundary must be established by your fiance, but the rest of it — expecting him to be at their son’s games, for example, is not a far-fetched expectation. (How much of a hardship that becomes depends on how far away she moved, and hopefully that was discussed before the move.)

Having another boyfriend and another child does not change your boyfriend’s responsibility to their child. And, it is certainly unlikely the mother of his child will walk away. Rarely do mothers think, “Oh I have another baby with someone else, you can just have this one.”

Finally, why is he a “poor kid”? It sounds like he has a mother and father who are attentive and love him, plus a brother or sister and other adults who love him as well.

What makes this situation complicated is the fact that you may not have been prepared to share the man you love with a past that requires present responsibilities.

Rule No. 4 of the 10 rules of good ex-etiquette is, “Bioparents make the rules, bonusparents uphold them.” In other words, mom and dad come to an agreement about the rules for their child and then it’s your responsibility to uphold them.

If you can’t, then take a look at that now, because if a bonusparent tries to dictate policy, the outcome is usually butting heads with one or both of the parents — not a good recipe for new relationship longevity.

We understand your desire to start over without the interference of the ex, however, it rarely happens when there are kids involved. Positively coping with the trials of a break-up is the reason we developed the rules of good ex-etiquette.

More than how to approach this with your fiance, it may be time to consider a change of attitude. Begin, perhaps, with asking him for suggestions on how you can help make the child’s transition from house to house easier for all.

Jann Blackstone-Ford and her husband’s ex-wife, Sharyl Jupe, authors of “Exetiquette for Parents,” are the founders of Bonus Families (bonusfamilies.com). Reach them at:

eebonusfamilies.com