I've eaten my cum out of a vagina and I enjoyed doing that very much. I have also rimmed my partner after I had cum in her butt, however she did NOT push my cum out while I was rimming her.
If she'd pushed it out there would always be the possibility that there may be something unpleasant mixed in... neither of us are into scat play.
Honestly, neither one of those are appealing to me. Seeing my man eat his own cum does nothing for me.
I don't really find it very arousing, but I imagine if he did either he'd only want to vaginally. We don't really do any anal play and if we were to I don't think he'd want to, nor would I really want to let him lick down lower. Lotsa' nasty things and all.