1. OK, you won. So what?
2. OK, you're getting married, what do I care?
3.You know what? I just couldn't care less.
4. OK, your English is better than mine. But I don't give a shit./ I don't give a crap./ I don't give a rat's ass./ I don't give a fuck.
5. OK, you're in trouble, but it's none of my business.
6. OK, you're leaving. But it doesn't have anything to do with me.