My ex and I were married for 13 years, have two kids, and somehow managed to stay best friends after splitting up. We co-parent like pros, even though our marriage had its ups and downs.Yesterday was our eldest’s birthday, and we all went out for a meal. My ex has been seeing this new woman for about four months. He told me right away because we’re all about keeping things clear for the kids. He asked if she could come to the birthday dinner. I wasn’t thrilled about not meeting her first, but I didn’t want to be intrusive, so I said sure. The new girlfriend seemed nice, friendly, and genuinely interested in getting along, which was a relief. If she’s going to be around my kids, she better be a good person.