I ain't on that shit! - You're saying you're not going to be involved in whatever st

You're saying you're not going to be involved in whatever stupid or annoying thing someone is doing.

I ain't on that shit! You're annoying and I ain't going to be part of your annoyance.

I ain't on that shit! You're doing something stupid and I ain't going to be part of your stupidity.

I ain't on that shit! You're making a mess and I ain't going to be part of your mess.