Girl is giving you blowjob but you tell her you don't want to finish her mouth (play the nice guy angle). Instead, you hold her head close as you finish in her eye (right eye preferable). As she stumbling around like a drunken hobo, you kick her in the shins really hard. As you're running away, peek over your left shoulder. If you've done everything right, you should see an angry pirate!
Yargh! I gave your sister the old angry pirate last night!