06/12/2013 10:03 am ET Updated Aug 12, 2013

Just because he loves kids doesn't mean he will love YOUR kids

A couple months ago I wrote about what I expected to be a sweet one-off hook-up with a hot motorcycle-riding Sicilian I was convinced I had nothing in common with.

I was right, but I was also wrong (hate that!).

Yeah, I got the fun date I was after, but there was something else that had me going back for more: Lou has a capacity to love children who not his own in a way that I have not yet encountered in men I date.

As I got to know Lou, he chatted about different kids in his life -- a teenage nephew in a troubled situation who lived with him for a few years, and is now a college student on full scholarship. Lou shows me pics on his phone of two preschool-aged nieces, and laughs about their antics when he takes them Sunday morning breakfasts. He's had several long-term relationships with single moms, and seems sad when I ask about those women's kids who he no longer sees. Whether it is simply his nature to easily love children who are not biologically his, or that these kids fill a void created by the absence of children of his own, I do not know. But he made me realize that my list of qualities I'm seeking in a long-term partner was woefully short.

Now, all the way at the very top of my list is: He can love my kids.

I date mostly men with kids, partly because I find it hot and helpful to see what kind of dad a guy is to his own children. Until Lou, I blindly assumed that if a man is an adoring, devoted fathers to his own children, those qualities automatically transfer to the children of other people. People like second spouses. People like me.

But as I get to know blended families and spend time as a single parent, I can see why step-families are often rife with challenges, and the divorce rates for second and third marriages is so high -- especially if those unions include children from previous relationships. Parenting is hard. Relationships are hard. Throw two families together -- that is some tricky business.

But I don't believe it is impossible with the right couple. The right man. Now, when I'm sussing out a guy, and I smell a potential long-term mate, "good with kids" and "great dad" simply are not enough. I need a man who has the bandwidth to love other people's children. My children.

A few Sunday mornings ago while hanging out, Lou called his nieces' parents to arrange their weekly outing. He put on speaker phone (Lou's no dumbass: he knows chicks love guys who are good with kids), broadcasting the squeaky, yammering voice that can only belong to a happy 3-year-old girl. "What are you doing, sweetie?" he asked her. "Hi-Uncle-Louie!-I-went-to-swim-lessons!-Are-you-going-to-take-us-to-breakfast!-I-want-the-pancakes!-When-are-you-coming-I-love-you-Uncle-Louie!"

"I love you, Honey!" he said, grinning his huge, adorable smile. "I love you, too."