Nothing's more disappointing than watching some dude cum on a chick's shoulder because he's so caught up in the moment! So I suggest you take cue from the COHF strategy of making the guys stand behind you and point themselves down onto your forehead. And if you're kneeling (not lying) the audience will get a full-view of your pretty face as well as allowing for cum to flow down over your nose, cheeks, mouth, etc. - so everyone's happy.

And definately go with the tray below your chin! Just my directorial two-cents.