<human>: I go to a small college. I recently matched with a girl on Tinder who I've known for a while. Unfortunately, I met her because she dated a friend of mine for more than two years. They broke up about 3 weeks ago, and he initially took it badly. More recently, he seemed okay with the breakup when I asked him how he was doing. We're close enough friends that it's unlikely he would lie about that to me.

The bad part here is that for the past few days his ex and I have been texting. She used the match on tinder as a semi-joking excuse to start flirting with me, telling me she always had a bit of a thing for me. I've not been unresponsive to this; she's attractive, and we already got along so the initial weirdness was dissipated. I also saw her at a party a couple days ago and we danced/made out a bit, which I'm already feeling some guilt about.

I'm unsure how to proceed here- I'm attracted to the girl, but it's also a moral thing, given that she and my friend broke up so recently. Any advice?

Give me a shortened version of the text
<bot>: Friend's ex (with whom he broke up only 3 weeks before) is flirting with me. Have reciprocated a bit. Unsure how to proceed.