Anal Sex Technique -- you must thrust ferociously and ejaculate with bravado. After completion, a very frothy semen will lay on top of the recipient's anus akin to the head on a properly poured Guinness stout.
Should you wish to add a "selfie" photo on the frothed semen, inquire with someone who would be willing to lend their Ripple machine to the butt.
~Consent first and always~
Nake: "Oy, mate! You wouldn't believe what this right made me do. They let me give 'em a Stoutie!"
Krïs: Truly profound. I'm going to ring your wagon and let 'em know you're being a little generous with your Stoutie pours!"