note: This is refrence to the siege of Troy whereby soldiers (semen) snuck into the city disguised as a gracious gift of sorts.
From _The Iliad_, by famous dead poet Homer, when the Ithacans gained victory by hiding in a huge wood horse so they could get into Troy.
Steve: Nah I totally trojan horsed that whore!
Kevin: "What do you mean? She looks hot!"
Ted: "The bitch is a walking petri dish! Last week she jumped me without a rubber and now the end of my dick is on fire!"