The Scottish Yon
While engaging in oral sex (between two men), one man squeezes a dash of horseradish onto the tip of their partner. They then proceed to blow them while simultaneously jerking themselves off until the taste of horseradish causes them to vomit at the moment of ejaculation.

When done correctly, both parties ejaculate at once, resulting in the recipient ingesting a mixture of their vomit, horseradish, and semen.
Person1: Hey! Did you hear Jonny and Alec did the Scottish Yon last night?
Person2: Is that why it smells like horseradish?