...for an attractive woman sitting next to me, I have no boundaries, except for really pungent perfume.

For myself, I've drawn boundaries mostly from my commuter train experience. I do my running in the morning, so I am almost always dressed in my running clothes when I get on the train.

In the summer, I always wear a tee shirt over my singlet, so people don't have to deal with my hairy armpits. I wear baggy shorts over my much shorter running shorts. I'm not at all concerned with exposed legs. What I'm trying to prevent is a second occurance of a "wardrobe malfunction" I had with a pair of running shorts a few years ago.

In the winter, I'm usually wearing tights. My winter coat generally covers my butt because I think that looking like a ballet dancer probably isn't very neighborly.

The huge advantage of wearing running clothes on the train is that very few people want to sit next to me. At the building, everyone gives me a wide berth in the elevator.