What are some weird/barely noticeable traits of the opposite sex that turns you on?

[Jaysk]

I'll start.

-Whenever a girl is wearing a white translucent t-shirt and you can see the back of their bra

-If they use Rejoice/Sunsilk as their shampoo and you smell it, especially if you smell it on the back of their neck

-The "maglalaba ako" way of tying their hair