Why did guys look so much when I didn't wear a bra?

Sbgirl
I know it sounds obvious, like yes boobs, but the thing is I didn't think it was that obvious and plus I'm quite small. I have this nice backless red dress, and I thought I can't wear a bra with that because the band at the back would look unattractive and ruin the look of the dress ( I know you can stick-on and backless bras but I didn't want to invest in one when I would barely use it). I have small boobs (b cup) so it's not like I need the support or that they were so big that they drew attention. I asked my boyfriend if he could tell and he said it wasn't that noticeable and the only reason he noticed was because he was looking.

Now guys don't often look at my breasts, unless I were to wear something low or bring attention to them as they are small. But when we walked into town, every other person, predominantly men, were staring at my chest in awe. I didn't think you could tell because my nipples don't even protrude very much (they are puffy) which has made me self conscious. But I told my boyfriend if he I was just imagining things and he also said all the men were looking at my boobs.
So how did they notice and did they like what they saw or did they just think it was strange?
Thanks
Why did guys look so much when I didn't wear a bra?
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