They aren’t that young so not so much an issue but honestly if you wear a well fitted neat sized cage then I can’t think it’s a problem. You might be very aware of it but they won’t have any idea it’s not just the seam of your zipper. I think wearing some tight sports underpants over the top of it would deal with any issues? And maybe in bed that with another layer either boxers or PJs over it.
You don’t have to do Locktober, in October by the way! Just because they rhyme doesn’t make it the law. In fact that’s what one of the things i’m putting together now is for, lots of similar ideas from very, VERY simple to more advanced that you can try together to explore all this and get inspired.