Dipping your pen in the company ink
OK, let’s start with the basics. I assume since you said co-worker that there is no reporting relationship between the two of you. If there is, my entire answer changes to leave this alone and don’t ever touch this shit again. You’re at work to make a living and build a career (and a reputation, BTW), not to get laid.
But let’s assume you’re free of any subordinate issues - please take a quick look at your company policy re: work place romance. Some companies have developed more stringent guidelines in this post #metoo era, so make sure you even HAVE the option to contemplate next steps. Assuming you do, please consider the following:
Are you ready for ALL of your co-workers to view you differently (which they will once you get embroiled in and become known for a workplace romance)? Are you ready to be in a meeting with someone who’s seen you naked and vulnerable? Are you ready for the messy reputational repercussions if/when this thing goes sideways?
If none of the above concerns you, then yes, you should figure out how to casually reconfirm what you think you said to her. And bro – if you’re gonna do this, then go balls out with a proper assumptive close, like a text that says, “Hey, I’m thinking we made some plans the other night? Does this weekend work for you?” If you get back a “?” then you know you need to re-ask soberly. If you get a hard no, apologize for your faux paus, claim drunkenness, and back WAY THE FUCK OFF. I don’t care how “close” you think you are, you play it very polite but cool and aloof - leave any further communication/connection in her court. Again, it’s a #metoo world now, you don’t get to ask twice without looking like a total douche.
Now, if you get a yes, please re-read the above considerations, proceed with caution, and be the best damn gentleman you know how to be. Because of the baggage that comes with workplace relationships, assume everyone will know everything eventually, so behave as if this will all be on the front page of the company newsletter (someday).
But most of all, good luck!