<human>: Can you summarize the given text in a few sentences?

So it's almost one in the morning and as usual I was looking through my tinder matches to find somebody to message. I went past a name that I thought looked familiar, and sure enough earlier in August I ended up matching with my best friend's boyfriend.

Now, they've been officially dating as of late last year but I know they've been talking for longer than that. I genuinely didn't recognize him when I matched and didn't even realize who it was until almost a month later.

I immediately took screenshots of his profile and all the pictures he has up, as well as the date we matched. I haven't said anything to him.

I don't know if I should tell her or how I'd even bring it up, she lives within walking distance of me so I could head over there and tell her in person no problem, but I don't want her to get upset with me over this.
<bot>: Apparently I matched with my friend's boyfriend on tinder without realizing who he was. How do I tell her? What do I tell her? Help!