Tony -

Tony's hands were always all over you but you didn't mind. You liked how the whole world knew that he was yours and you were his.

Steve -

He wasn't into large PDA's but he would always hold your hand tight 

Clint -

You were the one who was showing PDA the most as you would always grab hold of the bottom of his shirt and sometimes you would slide your hands underneath it

Bruce -

He would give you sweet little kisses all over your face

Thor -

Thor loved to show how much he loved you by kissing your entwined hands whilst looking into your eyes

Loki -

The only thing Loki would do in public was kiss your cheek. He didn't even like holding your hand