Opher, as always insightful question!
Yes! I do have thoughts about this:
1. First, as a disclaimer, I think you can think aikido is sexy in general without feeling sexy while doing aikido. I totally agree with the earlier post - aikido is conceptually very sexy. That doesn't mean that I am throwing people around in a constant state of arousal or that I ever think about sex while training.
2. I think that someone who is thinking about sex during training is presenting her/his partners with yet another variation on "the difficult uke". I think that learning how to deal with any kind of inappropriate or not fun or bad energy (as long as it's not hurting anyone) in a connected, positive way - learning how to work with It, whatever It is, is the cornerstone - it's what I'm doing spending all the money and time learning aikido. Once class is over, if Joe Neckbone is asking you out or making nasty eyes or rude, lewd suggestions, etc, then boundary setting is of course more than called for. But I vote train on unless it hurts. I train with a couple of people who have weird energy that feels personal (not quite sure if it's sexual, pretty sure it's gender oriented and it's definitely a little creepy) and when I train with them I learn a lot from it. I learn how to train without compromising my integrity, how to hold my own even though the situation is a little intense, I confront one of my biggest everyday fears, which is this kind of creepy attitude that women I think get a lot of. It adds a sense of intensity that is very challenging - every once in awhile!
If everyone I train with was like that, I would quit, it would suck. But one or two of these experiences every once in awhile has been a very positive learning experience for me.