If you grab dinner with a former flame, you could snuff the spark in your 
current relationship. According to a new Cornell University study, dining with an ex is more likely to spark jealousy in your girlfriend than just 
meeting for coffee. It might trace back to a fear of emotional infidelity: women may consider the act of eating more intimate than other forms 
of interaction, possibly because they associate it with dating and family, 
says study author Dr Kevin Kniffin. Catching up with a lass from the past? Schedule a coffee date meet-up for late morning, which is less jealousy-inducing than an afternoon rendezvous, the study also found.