go ahead and ...：思い切って～する

A few days ago, I found a big snail in the garden.
I haven’t seen or noticed one for a long time
because I was not interested in such a grotesque creature.

I said to my son “ go ahead and catch it “, but he couldn’t.

But in fact, I was relived that he couldn’t.

What if he brought it into the room and said he wanted to have it as a pet?
I hope he won’t say that in the future….
Maybe I need to prepare for some excuse to turn him down in such a case.