'AITA for not telling a new friend that her husband used to cheat on her with me?'

"AITAH for not telling someone in my social circle her husband used to cheat on her with me?"

OP writes:

Over ten years ago, when I was in my early 20s, I started casually sleeping with my ex-boyfriend—like once or twice a year. We were together for most of high school and were each other's first everything. So, when I got lonely or whatever, I found myself drawn back to him, like an old home.

At some point, he started dating a girl, so I didn’t pursue things with him anymore. Then one day, I was at a party, and she was there and started asking me really insensitive questions. She wanted to know if he was my first, if he told me he loved me back in high school, etc. It made me really not like her.

I know this is stupid, but several months later, when her ex reached out to me, I decided not to say no. A year or so later, we ran into each other again and slept together again. Several years after that, they got engaged, and I decided to block all contact with my ex.

Recently, she joined the local running club I am active in, and we have started spending time together as a group. I haven’t told her or anyone about her husband. AITAH for not telling her? And yeah, I know I am the AH for sleeping with him.

Here are the top comments:

Secret_University20 says:

“I decided to not say no” is conspicuously oddly passive here. Is there a reason you didn’t say “I decided to help her boyfriend cheat”? Would saying that make you feel like an a^#$ole?

Fractured_Windows says:

It sounds like you’re either not over him or you’re using it as a mental one up on her. It’s been 10 years…. It’s time to let it go.

Randomginger_16 says:

YTA for being a trifling drama queen.

Shot_Independence274 says:

Mate...It's been a decade...Let the dead rest...Don't dig out bodies that are sleeping.

What do you think?