For a while they are trying to convey something to each other thro' their eyes. Then they strenghten each other thro' their acts...
this hold of Sid says, "I'll be there to hold you before you fell down. I'll be always there to care you and no need to worry my love"
and what abt this red impression?
She is replying him, "I know and I always Trust u that u'll will help me and take me out of this mess too... This mark hints Sid abt her trust on him silently before she leaves the place.