It is possible that he noticed, but had the discipline to keep his eyes on my face. There are, in fact, some guys who have that discipline. I'm one of them, but just barely. I can remember, years ago, I used to carpool with this guy, and one day my ex-wife happened to be home and outside one day when we had just returned from work. For whatever reason, she was wearing a very low cut top on that particular day (and high heels, as well!). I figured it would be rude if I didn't at least introduce them, so I said, "Come on, Phil, we better say hi to my wife."
The conversation was not long, but after Phil left, my ex-wife commented, in a complimentary way, that he maintained eye contact the entire time and did not look at her bosom. I talked to Phil about it the next day, and he admitted it was very difficult not to look. I find myself in the same situation with shoes. Although my life in that respect is getting easier and easier all the time. I have to look at my own feet.