Is next weekend this coming weekend or weekend after next?

The weekend of the week you are currently in is this weekend, Next weekend would refer to the week after that.

Then of course it depends on who you are talking to, If you came up to me on monday and said lets do something next weekend, I would assume you mean the very next weekend.

If you said the same thing on friday I would then assume you mean the weekend after this coming weekend.

Confused?

That is why I end up saying things like two weekends from now, or the weekend after this. Unless you know how the other person thinks you can not be sure so clarify.