So if Aerith was alive and Cloud chose her... cant' you totally see Tifa throwing a fit "You Outta Know" style?
How the hell do you see that?
Tifa was the one who stayed out of the way when Aerith was flirting with Cloud. She wants Cloud to be happy - no way she would throw a fit, she could never do that to Cloud and Aerith. She's the one who keeps her feelings aside, and she's the one who wants Cloud to be happy. Tifa has always cared for Cloud, and she's ended up having her feelings hurt before because of Cloud - but she only tells him what's in her heart when she feels the need to. It's already been mentioned before that she was jealous, but she never actually bothered to bring those feelings up - why? You
never see Tifa throwing a fit over Cloud and Aerith's relationship. More so, she stays aside and watches as their relationship 'blooms,' when he's the fake Cloud.