This is something I have always wanted to try with my wife, but I can't figure out how to ask. She kisses me after I eat here out, well sometimes, she gets really wet so my face looks like a glazed doughnut some times and that will make her think twice sometimes. When she finishes first sometimes she will hop off and finish with her mouth and I find that incredibly sexy.
I guess I just need to surprise her and not ask with a quick peck after a facial or crawl between her legs to finish her off when I'm done.
She doesn't like it in her mouth, much prefers it on her chest or face. Maybe this would bring her around.