TILF stands for Teacher I'd Like to Fuck. It's the same idea as MILF, but you know, some of us get lucky and we get an outrageously attractive teacher for a whole school year.
Student 1: "I heard we're getting a hot math teacher."
*Hot teacher walks into the classroom in slow motion while her hair flies in a sexy motion from the blowing of the fan while "American Pearl-Automatic" plays in the background.*
Student 1&2: *pound fists together with a sly grin*
Student 2: "I can't believe we finally got a TILF!"