for grace, after a party

You do not always know what I am feeling.
Last night in the warm spring air while I was
blazing my tirade against someone who doesn’t
interest
me, it was love for you that set me
afire,

From "For Grace, After a Party" by Frank O'Hara via Books vs. Cigarettes. It's the line about the tirade against someone that doesn't interest me that gets me.

Photo by Mikael Kennedy via Horse Hunting