Why did he ask me out after all this time?

Was out this past weekend on a date. As I got up to leave, I saw that a man I dated on and off for a couple of years was on a date at the same restaurant with someone else and sitting at the bar behind me. I didn’t see them enter so I’m not sure if he spotted me. Two days later, I received a text from him, “checking in”, after no contact for over a year. A few pleasantries later, he invited me for a dinner date and no mention of seeing me at the restauant. Assuming that this is not a mere coincidence, do you think he’s acting out of jealousy? Should I accept?