Q and I were having this conversation over the weekend, so it sounded like a poll to me.
Say your SO gets totally plastered and ends up making out with someone, then can't remember anything the next day:
It's...
and...
(I suppose the pre-supposition here is that you're not already in an open relationship, but you can answer without that preface if you so desire, or perhaps your rules don't include kissing, so explanatory comments are welcome.)