My wife has this shoulder drop top that shows both sides of shoulders. Usually when she wears it, she would have stick-on bras (don't know what its actual name is) so no straps would be seen.
Lately we had a backyard party for a friend's child. At the end of the party, we gotta flat those inflatable toy. One of them is a big pool pad for kids to jump up and down. Everyone was laying on top to squeeze the air out. I saw my buddy was there, he's the one I mentioned before that admit to me he once fantasizing my wife's boobs. So I ask my wife to go giving him a help.
She went straight to him, fell down on the pad. I could see her top were all opened that I bet my buddy could have a nice view what's inside.
Later when we got home, I just couldn't wait to feel up her breasts. What surprised me was that when my palm went up, all I felt was her pocky nipples. I asked her if she didn't wear any bras. She said during the middle of party, she felt those silicone made bra pads too sweaty and hot so she peeled them off already.
Which means..... what my buddy saw was her bare breasts and nipples
Even think about it, I instantly got really hard and started boning her on couch.
And sure my wife know I have fetishes showing her off and sometimes she would do it on purpose and later told me who saw her "accidentally flashed"