I told him I was pregnant and he acted like this....what's up with that?

This guy friend (who I've had a ual past w/) is married now & I'm married now. Today, I went to Walmart & I saw him & his wife and she asked how we were doing. I told her I was pregnant. When I got ready to leave, they had already gotten in their vehicle and were going down the aisle. I was pushing the buggy to my vehicle and my mom was w/ me. He decides to drive down the aisle I was on. Well, we weren't in the middle of the aisle or anything but, he was going real slow and wouldn't p us. When we got closer to the car, he got next to me, Smiled real big and said "BYE Talk to you later". It was the weirdest thing, even my mom asked what that was all about. He was looking right at me when he said that, then after he said that, he sped up and drove off. Do you think he was doing that for attention or something...we are both married so I don't know why he acted like that. Do you have any ideas? My friend said he may wishing that he was the one that got me pregnant, what do you think?