The term "moot cute" applies when you have an attractive person in your life with whom you have no romantic or sexual relationship. You typically use this phrase as a response to someone's inquiry as to why you're not involved with that individual in an intimate and/or physical way. The reason you're not involved with this "cute" person is because it's "moot." In other words, the person has other commitments, mental issues, or is of a different sexual persuasion.
Tim: Yo, Billy! That chick Sally is SMOKIN'! Why aren't you nailin' her?
Billy: Aw, shucks man, Sally's moot cute. She's crazy, and she's about to move to New York.
Rachel: OMG Amanda, who is that guy Tim I saw you having dinner with? He's so chiseled! Is he your latest man?
Amanda: Ha! Moot cute. Tim's gay.
Bill: Man - who was that babe who gave the speech at your bday party? And why wasn't she your birthday present, if you know what I mean??
Phil: Dude, moot cute. That was my cousin. And we're not from West Virginia, if you know what I mean...
Since "tall" is the smallest size at Starbucks, you use the phrase "Starbucks Tall" to refer to someone who alleges to be tall, but is, in actuality, small. This could be in response to a friend/other well-intentioned individual who claims that a romantic prospect is "tall," or as a skeptical response to someone who describes himself as "tall" on his online dating profile.
Shelly <reading Jim's match.com profile>: This dude Jim's says he's tall! <Scoffs> Look at him standing next to his ride in this shot, though! <Sarcastically> Um, yeah - he's *Starbucks* Tall!
Shelly's Mom: Now, honey, just go out with Phil once. He's a great guy with a great job. Plus, he's tall.
Shelly: <skeptically> Mom, do you mean "tall" or "Starbucks Tall?"