Niall:
Neck. He loves the feeling of your soft skin under his lips. He loves how when he gets to just the right spot, you melt underneath him. He loves sucking and nipping at your neck making you moan his name.
Louis:
Nose. Whether it's at home or in public, Louis loves to just bend down and peck your nose. He says it shows a cute side to your relationship. He also sees it as a protective thing to do when other men are around without being to forward.
Liam:
Cheek. Liam just loves to kiss your cheek. He likes to be able to kiss you in public with out kissing your lips, because when he kisses those luscious lips, he just can't hold back.
Zayn:
Lips. Zayn just loves your lips. Whether it's kissing them, or when their doing something which he enjoys majorly. He loves the feeling of them on his. They're easily his favourite part of your body.
Harry:
Forehead. Harry is a fair bit taller than you, so it makes sense that he loves to kiss you there. When you're walking in public together, he loves to just lean down and kiss you lightly. He loves kissing you there to show other men that you are his and his only.