My (21M) only good friend (20F) I’ve made while studying abroad has feelings for me. Should we stay close? And should I tell my girlfriend?

I’m (21M) a third year university student from France doing a year abroad in the United States. I have a girlfriend back home that I’ve been with for the past 3 years.

I’ve had a very lonely and difficult time in the US so far, mostly because of bad luck: most other exchange students who’ve come to the university are a group of girls who all stay together, and the few other exchange and transfer students are either far too wealthy for me to be able to do much with them, or are people I simply can’t really “click” with (for reasons such as wildly differing morals). I’ve tried to make friends with Americans as well by joining clubs and trying to speak to people in my building, but everyone has their friends already and nobody wants to put much effort into being friends with someone they’ll only see for 8 months. Thus, with not much else to do, I spend most of my time working at a job on campus. That’s where I met someone we’ll call W (20F). We started by working together a couple of times a week, and we’ve since become genuinely good friends (getting drinks together once or twice a week, hanging out at each other’s apartments, watching movies together, etc).

When we first started hanging out, W would act in a kind of flirty way, but I made sure to bring up my girlfriend in conversation and talk about her to make sure she understood that I was committed to my partner back home, and she stopped behaving in that way completely. I thought everything between us was thus completely platonic on both sides.

This past weekend, W invited me out to go clubbing with her, and I haven’t been out too many times since I came to the States so I agreed. We both had quite a bit to drink and went out, and had an honestly very fun night. But, at a certain point during the night, she told me “it sucks for me that you aren’t single”. She later apologized for that profusely, and I tried my best to brush it off, but she later got very upset while asking me if I thought less of her because she danced with several different guys at the club (something I shouldn’t really care about since I’m not her boyfriend?).

We’ve seen each other since this weekend and everything seems platonic and “normal” between us, but I’m kind of torn on what I should do. On the one hand, I feel slightly uncomfortable with the situation, and am sure my girlfriend would be as well if she knew about it. But on the other, W is someone i genuinely really like and really enjoy spending time with: not only is she the only proper friend I’ve made while studying abroad, she feels like someone I could remain good friends with for a long time. We have similar interests, senses of humor, personalities, etcetera.

So, what do you recommend I do? Should I remain as close friends with W? Should I put a bit of distance between us? And should I tell my girlfriend about any of this? Any advice would be appreciated.

TL;DR my only good friend I’ve made while studying abroad has feelings for me and I don’t know how to proceed because I have a girlfriend