9. Lily Aldrin How I Met Your Mother
Lily Aldrin may seem sweet-natured and devoted to her friends (it comes with the territory when you're a kindergarten teacher) but she has several qualities that would make her an awful flatmate. For starters, she has very few boundaries when it comes to sex. Although when you're young and living in shared flat, you can't really be too prudish about sex, the last thing you want is for your flatmate to flirt (and we're talking borderline verbal sex here) with their partner while you're in the room, and later have sex on your kitchen floor. And your sofa but the kitchen floor's the biggest issue. Another quality of Lily's that would make her a poor flatmate is her incessant meddling in her friends' personal lives including engineering a couple's breakup if she thinks the relationship won't last or turn out well, and stealing close friend Barney Stinson's book of scams that he uses to bed women after taking exception to it.