AITA? Sleeping with a racist white guy's girlfriend...

So I'm 22 and at uni in the UK. Jamaican background but grew up here. Feel like I fit in pretty well.

I know racism is pretty systemic here still but I feel I get by ok and don't encounter many overt racists but a few months ago with the new academic year I've met this white guy (Boy really. Very immature) who acts like he walked straight out of 4chan or some alt right corner of Twitter. He's active in the debate society, takes any opportunity to try to troll any of the social oriented societies. He comes out with every conspiracy theory in the book: great replacement, globalist elites, cultural Marxism, he even talked about "all the non white people of TV" being propaganda. And if it's in real life at the society meetings he does it with this incredibly smug smile on his punchable face. Infuriating.

So I found out a bit more about him and he came to uni with his high school girlfriend, they applied to the same place together. And she is... well... Haha. A bit of a stunner. A really beautiful blonde young lady who is living in one of the other accommodation blocks.

So I thought why the hell not give it a go and cut a long story short me and here have been at it about twice a week for the last two months. I don't think he knows yet given he's still his cocky little self on the debate group and all that. I don't know if I'll ever tell him or let him eventually find out from her.

I know it's a not a great thing to do to help someone cheat but... well... I can't wait to see his face.

So... AITA?