MsR - the good thing is that when they're teens you won't have to lock them up. The echoes of "ew, gross" at the mere thought of the olds having sex will keep them out
My mum would have been a bit but would never have nosed around like my OH's mother. Plus in her eyes I've corrupted her "baby" and am a bad influence. I'd have had no problem telling my mum to mind her own and with that kind of relationship would have loved her to pop in.
OH's mother really WOULD like to see me burn at a stake but in the meantime she's trying her damndest to mark her territory on her son's house in an effort to bump me out of the way.
I must be getting old as I'd have had no problem telling my ex's mother to bugger off but I'm getting more diplomatic with age (even though I really don't like her and hate that she's thrown my fave vibe's charger away and cost us £1000's with her interfering and nastiness, but that's up to him to man up to).
Back to storage... a nice lockable trunk would be nice. Or maybe some vintage suitcases that you could stack (and lock). They'd be heaved up the loft for the teenage parties, though. Be prepared is my motto!