StevieC wrote:
<rant>
i texted my so-called best mate (or my only mate, read whatever you prefer), i said wot u up to, he said im busy.
so i went away to this acoustic music night (not lots of people go - so you can see the attraction

).
next day i messaged him and he wanted to know what i did, so i told him and he got mad cos i didnt tell him at the time (ie he wanted to go).
but i said that he said he was busy, but he said he wasnt actually busy, and that i should have known otherwise...
well why say you're busy if you were in fact doing sod all?
</rant>
If that is exactly what you texted him, it seems to insinuate, what is he doing right now in the present. It probably would have been better and more clear if you asked something like what are you doing tonight?
And even if that is what you asked, you may have said something like "well im going to this acoustic night if you're plans fall through or you change you're mind".
Though in reality I probably would have not even have said it, and it seems unreasonable of him to take a bit of a pop at you.
Unless he was maybe being a bit sarcastic?