- When Phil Diffy and Keely Teslow become a couple in "Back To The Future (Not The Movie)".
Keely: We do kinda hang out a lot... together.
Phil: Yeah. I guess someone could... mistakenly... think we're one of... those things
Keely: Yes yes, they definetly could... mistakenly
Phil: Unless... do you want to be a couple?
Keely: Do you?
Keely: I do!
Phil: Me too!
Keely: Yay, we're a couple!
Keely: Phil, the whole school just voted us cutest couple. I think they know.
- When Phil Diffy and Keely Teslow kissed in "Back To The Future (Not The Movie)".
Keely: Phil! You're still here! Does that mean you're not going?
Phil: No, no I'm still going.
Phil: I didn't want to leave without saying goodbye for real.
: [kisses her passionately and everyone cheers]
Phil: [pulls Keely into a hug]
Keely: [whispers in Phil's ear, so that only he could hear] In the future will you wait for me?
Phil: But... Won't you be really, really old?
Keely: [Gives him a knowing look, and smirks]
Phil: But that shouldn't matter...See ya, Salt.
Keely: See ya, Pepper. [pulls him into one last kiss]
- When Keely kisses Phil on the cheek in "Tia, Via, or Me...Uh"
Keely: [Keely arrives and kisses Phil on the cheek, pleasantly surprising him.] That's for introducing me to Via.
Phil: I get a kiss every time I introduce you to a girl. [grabs random girl heading down the hallway] What's your name? Have you met Keely?
- Keely telling Phil how wonderful he is in "Christmas Break".
Keely: Phil Diffy, Your the most wonderful boy I have ever known.
- Keely's reaction to Phil's birthday gift in "Happy Nirday".
Keely: This is the sweetest, most wonderful, Incredibly beautiful thing anyone has ever done for me.
- Phil telling Keely how much she means to him in "Time Release Capsule".
Phil: I thought being remembered a hundred years from now wasn't important. But I'd give a hundred years of memories just to remember the most important, special, wonderful person I've ever met...Keely Teslow."
- When Phil and Keely acted like they were married in "Dinner Time" and Keely calling him a Sweetie Pie.
Phil: I wish you did remember though, for a while there it was kind of like we were married.
Keely: Was it fun?
Phil: Yeah... it was fun.
Keely: Cool, well I better get to class.
Keely: See ya at lunch sweetie pie [stops then turns towards Phil] I-I mean Phil.
- Phil saving Pim in "Phillin' In", especially considering that she had spent the entire episode sabotaging him.
Pim: (waving from a high cliff) I'm up here!
(Phil goes to save her)
Keely: You can't climb up there, it's too high.
- Compounded when after climbing the cliff, instead of yelling at Pim for sabotaging his efforts to earn an afterburner and crashing the skyak, Phil simply hugs her.