Phil of the Future/Heartwarming

"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: No! Phil: No... Keely: Do you? Phil: No... Keely: Yes! Phil: Yes? Keely: I do! Phil: Me too! Keely: Yay, we're a couple! Phil: Shh! Keely: Phil, the whole school just voted us cutest couple. I think they know."
 * When Phil Diffy and Keely Teslow become a couple 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. Keely: Oh. Phil: I didn't want to leave without saying goodbye for real. Keely: Yeah Phil: [kisses her passionately and everyone cheers]"
 * When Phil Diffy and Keely Teslow kissed in "Back To The Future (Not The Movie)".

"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]"

"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?"
 * When Keely kisses Phil on the cheek in "Tia, Via, or Me...Uh"

"Keely: Phil Diffy, Your the most wonderful boy I have ever known."
 * Keely telling Phil how wonderful he is in "Christmas Break".

"Keely: This is the sweetest, most wonderful, Incredibly beautiful thing anyone has ever done for me."
 * Keely's reaction to Phil's birthday gift in "Happy Nirday".

"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.""
 * Phil telling Keely how much she means to him in "Time Release Capsule".

"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. Phil: Yeah Keely: See ya at lunch sweetie pie [stops then turns towards Phil] I-I mean Phil."
 * When Phil and Keely acted like they were married in "Dinner Time" and Keely calling him a Sweetie Pie.