When eating pussy do you like it to be smelly? NO
Would you like to be fucked in the ass and mouth simultaneously ; )? NO
Would you like your jerk buddy to ejaculate before you so you can have his sperm in your mouth to finish your own wank and cum you turn? NO
In a MMF fuck, it's better to let the other guy finish first so you can then fill the sloppy second cummed pussy? YES