To be fair, it took her a while and she didn't specifically cite the hair loss as the source of it. The impact it had on our relationship was interesting. I was very upfront with her right when I first met her. I told her I was losing my hair, though it was barely visible at the time, and she wasn't bothered, in fact she found my honesty endearing. The issues arose when I made the decision to buzz it instead of continuing with the hairspray-dependent hatchet-job of a combover I'd begun sporting after the loss really started to show. Again, I'd given her plenty of warning in advance, but it did little to soften the blow. Her reaction upon seeing me was one of disgust and revulsion; she concealed it well but it was there. This would've been about our 5th date or something and we spent most of it in silence. I did my best to try and ward off the souring atmosphere, joking about my new hair do and trying to initiate some physical contact, but the warmth was gone. At the end of the date, I confronted the issue directly and apologised for cutting my hair so short. She actually responded well to this, laughed and ordered me (with tender reproachfulness!) to let it grow a little bit longer and kissed me. I managed to bring her round, but it took a lot of effort and charm to do so. My hairloss was actually not much of a problem between this date and when we started university together, the issues were more the result of its impact upon my behaviour and personality, as opposed to my appearance.
Before I go into any more detail on our relationship however, I should probably qualify all this with a bit of key context. Firstly, I was this girl's first boyfriend, her first 'love', her first everything actually. She hadn't even kissed a guy before me (which I still can't get my head round because she is now a professional model) and was therefore likely always going to be a heck of a lot more lenient than I'd imagine most girls would be. Secondly, she went to an all-girls school and didn't really know that many guys. Again, with little competition, I was always going to be allowed a bit more leeway. Thirdly, and most importantly, we got on incredibly well. I've never actually had such a connection with anyone before, to the extent that I can honestly say she was my best friend as well as my romantic partner. Given all this, I don't know how much can be extrapolated about the reactions of girls generally in response to such a drastic appearance change. My baldness certainly wasn't appreciated. I'd often catch her instinctively reaching for a forelock that just wasn't there when we were kissing and she even started researching treatment options, though this was just as much to try and lift my mood and support me as it was for her own benefit. As I've said, it was only really at university that it became a serious issue - and obviously, for most of that 5th date.
I'm happy to chart out the whole relationship, and its subsequent breakdown, if anyone's interested. It's relatively cathartic for me and could provide some useful insights into the damage which hairloss can do. I've also got a lot of advice I'd like to give people on how best to deal with it all, what I would have done differently etc. (and there's a lot).