No it wouldn't turn me off if I noticed a girl sweating it would make me feel more comfortable and confident around her because sometimes I sweat for no reason also. It sucks when I'm wearing a darker colored shirt and one of my armpits decides to start sweating for no reason and leaves spots on my shirt! lol. I actually have seen this happen to girls a few times and I just ignored it like I hope they do when it happens to me. It's not a big deal and not a turn off to me.