I noticed on multiple play-throughs that during the end battle with Seph, I got different party members than I had when I first beat the game that joined the fight a bit later.
The first time playing it I got Tifa first, then Barret.
On my first play through when Tifa came into the party she asked Cloud "Need some help?" Which Cloud responded "I don't know about need..."
Tifa
My second time playing I got Aerith, then Tifa.
My second play through when Aerith came into the party first she asked "Did you missed me?" Which Cloud responds "Not really."
Aerith
Cloud's reaction to both girls situations could come off very aloof at times.
However, I think what Cloud says to Aerith is down right out
dismissive IMHO.
Edited to add links.