My boyfriend is about to come home from a 9 month deployment, and he'd been distant but has kept up with communication with me. Why would he be like this?

Let me continue, so he has been trying to keep communication between us which is good because we really need communication, but he can be very distant as well. He's deployed and I'll message throughout the day, things like "I hope your day is going good" and "I love you". He'll respond but never start a conversation. It's always me. He is about to come home from his deployment and all the spouses and girlfriends/boyfriends know when their soldier is coming home the date and time, when I asked him he would only tell me the wave he was, and said he couldn't tell me the time or day, but in an annoyed tone. And when I told him I wanted to be there to welcome him home he said he really doesn't want anyone there but he doesn't care. I don't know how to take this. I would think your SO would be happy and excited to you after 9 months if being gone. I need help in understanding why he would be like this and what I can do to help

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There is a 12 year difference between us as well. He's 26 and I'm 39
My boyfriend is about to come home from a 9 month deployment, and he'd been distant but has kept up with communication with me. Why would he be like this?
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