[PPActionnGuys]

Right, I'd love to tell my parents I get sexually aroused for no apparent reason too

This is why kids come to the internet.

I can't help you on avoiding it happening since I'm not a bloke, but my ex told me he used to tuck his inappropriate moments under the waistband of his trousers, to keep them hidden.

Will not work if you wear your trousers halfway down your arse like most kids these days though.