Confusing German guy... German style or just not that into me?

So A guy at work I have become friends with seems to be very attracted to me and I like him to. He's pretty shy and can be very nervous around me. I asked him on a date to the zoo and he said yes and seemed pretty surprised. He couldn't make the date because he got super busy at work and was stressing over giving a seminar. He said he defiantly still really wants to go but is busy He's a scientist that is currently wriiting up to submit to a top resurch journal being the sole publisher and with no collaboration on his work it's very time consuming. I know he's working every weekend as I can see times on his data logs. it's now been a couple of months since I asked. If I ask him if he still wants to go, he says yes, but there is still no sighn of us actually going.

He has pointed out that if I really want to go to the zoo I could go with someone else as he's not really free that much till next year. But I said I want to go with him, wich he was pretty happy about. He's German and pretty diarect so I guess I should take his word on it but can't help but feel a little put off. He had time for friends to visit from Germany the other day. last night at the Christmas party he didn't talk to me. He made eye contact and waved across the room but never came over. I saw him talking to some people I know and went over to say hi to them all, and he just walked right off seemingly ignoring me! I was ready to leave when I could see him saying good bye as well. So I just went right up and asked him to walk me home. He lives near me and was happy to do so. All the way home we chatted and laughed. It's great to hang out with him and get to know him. At my door was a little awkward so I asked him in, as he likes my pet cat. But he said no as he was tired and needed to get home. ok so he's German and pretty dam strait talking, but I'm feeling a little bit mixed signals he would have left party having not said a word to me and this makes me sad. I'm 100% sure he fancies me but wtf!
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We have flirted for nearly a year and it's taken a lot to move on from us both be pretty shy and his nervousness. Now he's relaxed a bit and I bit the the bullet on the date asking. thing are really much easier between us. The work party really threw me as I wasn't expecting a hook up or wanting that but I certainly didn't want to be ignored. Now I feel pushy as I asked him to walk me home and asked him to see the cat.
Confusing German guy... German style or just not that into me?
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