*laughs* I think, as a gender stereotype, men in general are just much less chatty then us females are. However, there is also a great divide between o/l & r/l. As an o/l partner, how much do you NEED to know about his r/l? How much are you ENTITLED to know? How much is he entitled to know about yours? He may be uncomfortable with telling you more about himself or his life to protect his family's privacy, or the seperation between r/l & o/l worlds. If you were r/l, I would say it is a different situation, but being o/l has these sorts of challenges. If it's bothering you, eating at you, or irritating you, you should talk with him about it. If he gives you an answer, then you have your answer. If he's evasive, shady or dodgy, then you also have your answer. O/l, in this case, is a different animal... and people keep things private for various reasons...
In your case, Claire, it sounds like he is being pretty open & honest with you--he tells you why he is going to be gone & when, and that he has a wife who doesn't know (that's INCREDIBLY open & honest) and who he doesn't want to know, etc... He also probably has NO idea how one-sided he sounds, asking you for details of your life when he doesn't give you details of his. He probably just wants to get to know you better as a person & as a sub. So talk with him about it: discuss that the unevenness is making you uncomfortable, set a limit at which you guys won't push eachother with questions about r/l... you have to find a balance that works for you...
Everyone should beware of a partner who never tells you anything & is completely evasive of ANY questions... but it doesn't seem like that's the situation here... so Claire... it's time to chat w/him & say, "Sir/Master/whatever-you-call-him, I am okay with sharing more r/l info about me, but in return, why don't you tell me something more r/l about yourself?" There are a LOT of ways to approach this, but you have to find the one that works for you...
Good luck!