Its a weird question I know but hey am curious my boyfriend does that all the time when he's with me.lol sometimes I think he's nervous but its cute he says that only happens when He's with me..What you think? Please don`t say nothing stupid thax u!
from what I have come to understand, throughout my life, is that a sigh is a signal from an individual that they want attention. I've realized that people sigh when they want someone to talk to or vent their frustration. I've even noticed that I will do it from time to time. next time he it does ask him what he is thinking about. he has to be thinking about something while he is doing it.
I read what the others before said but when I first read your question this is what I thought. It's usually means like the person is getting impatient or bored. lol! Like, "Hurry up!" Or if you were talking too much. ha! Try to remember yourself when you've done that. But it also could be a gesture that you just did something cute. Maybe he gets nervous around you and gets out of breath. :-)