<human>: Condense the text into a few key points

This technically happened yesterday since it's now past midnight here in England.

So I was out with my friend and we saw some of our old friends just hanging out. They were making their own Cards Against Humanity (you all know that game, reddit, I know you do, so I don't have to explain it) cutting up loads of sheets of card into little cards and writing things that reference people we all know personally. It was fun, lots of jokes being thrown around here and there, even things about themselves.

Here's where I fucked up... They really wanted one for this guy (let's call him John) and I blurted out "John's cheating habits". I found it funny because he's cheated on every girl he's been with and that clearly states it. Big mistake. Everyone goes "OOOOOO" and I begin to wonder why. It turned out, the girl sat DIRECTLY in front of me (let's call her Sam) is currently SEEING John.

My heart sinks. I've basically just told her about his history with girls. It's not that much of a bad thing as it could save her a lot of heartbreak, but he might have changed, who knows?
<bot>: Tried to make a joke, but instead I told a girl that the guy she's seeing has cheated on every girl he's been with.