Herb spent his 85th birthday on his knees watering flowers and pulling weeds, confronting the unexpected and premature summer heat. The sweat-drenched smile on his face demonstrated he was one happy man – in want of nothing more. But 85 is a milestone and this weekend his family is planning a celebration to honor this energetic and loving man.

I’ll be there with my significant other, and with my children and their significant others because Herb is my step dad, and has been for the past 23 years when he and my mom, both widowed, tied the knot. Because of their union, my sister and I inherited three step siblings and siblings-in-law, and six step nieces and nephews.

Every family event, from weddings to bar mitzvahs to major birthdays, has brought together Mom and Herb’s children and grandchildren who live throughout the United States and France. Amazingly, we all get along.

The first Thanksgiving after my husband died, they all came to my house (the dinner table stretched from the dining room, through the living room and into the foyer) so my kids and I wouldn’t be alone.

When my son broke his arm playing hockey in New Jersey the same night my daughter was rushed to a hospital in Baltimore (where she was a college freshman), I couldn’t be in both places at the same time – though, being a mom, I tried. So my step sister who lives in Maryland went to my daughter’s side.

When my sister’s daughter moved to Boston and didn’t know anyone, our step sister-in-law welcomed her and started a practice of including her in holidays and events.

I know that we step sibs have the distinct advantage of never having had to share a bathroom, or argue about riding shotgun. We were in our twenties and thirties when our parents married, all out of the house and developing families of our own. But still, it matters who sits at the helm.

At ours, sits Herb and Thelma.

Together they make one smart adorable couple who walk every day rain or shine, stopping for coffee and the morning newspaper, read books they’ve borrowed from the library, go to independent films that provoke thought, play golf and bridge, and so much more.

On Saturday when Herb blows out the candles on his cake and we stand around and cheer, I know what we’ll all be thinking.

What are we going to do for his 90th!?