A very similar thing happened to my DH last week so I know how you feel! DH at a works Xmas event and one of his ex female team members (he was her boss) is getting increasingly drunk.
I’ve always known she has fancied him (she is also married to another senior male that works in the company). Woman’s intuition - I’ve picked up on it over the years at social work events where partners were invited. My DH always brushed it off (a very professional manager).
She was with another female team member and was clearly drunk, declared she needed to go to the toilet. The female with her offered to take her.
Drunk female colleague refused help but publicly (in front of her new male boss) declared she wanted my DH to take her to the toilet and tried to grab him and pull him along.
Obviously he refused and told her to go with female colleague, but it took some persuasion. It was apparently quite obvious that she wanted DH to take her to the toilet because she had other intentions.
Once she finally left with other female, her new boss said to my DH “well that was awkward - what was she thinking?” - my DH agreed, all in a professional manner.
My DH told me this all on returning home. I’m just really annoyed at the sheer audacity of a woman who has met me in the past, thought she would chance her arm at an encounter with my DH without a second thought of her marriage, his marriage - their work reputation. I don’t care if she was drunk (personal responsibility?).
So I totally get where you are coming from OP - it’s not acceptable. My DH won’t go to HR because he shut it down. But my question is, will they try it again at other events?