The size of basketballs

It is a joke. By itself, this sentence is nonsense. In its context it is humorous.

"... the size of basketballs" usually means "big." There are a lot of measurements that seem to take the form of balls used for sports -- golfballs, baseballs, etc. A "basketball," in this progression, is the biggest one.

So the person is saying that they have a lot of scruples. (Very scrupulous.) Another way to say it is that the person is very moral.

I'd imagine it'd come up in conversation something like:

B: {outlines some plan}

A: That's a terrible idea.

B: No it's not.

A: Sure it is. Don't you have any scruples?

B: I got scruples the size of basketballs.

I think the joke is that it is an oblique reference to testicles.

Yeah, there's that too, but I thought the underlying meaning of "big" still held true (basketball-sized testicles are big but basketball-sized cars are not) so I focused on that. But there is an inference of that too, yes.

You're cute when you're blushing

Blushing? I'm not, really. Just tried to keep things relatively simple...

Oh....sorry....carry on

No need to get teste.

bollocks