Yeah that would be quite an extreme thing to say to your brother.. maybe it’s me who’s old fashioned but if my sister or I were to have said this to each other when we were younger then in my case.. I’d be extremely embarrassed and quite possibly traumatised if she said this to me, other way around then my sister would have probably beaten me to a pulp and proceeded to tell the whole of our social circle upon arriving home ha ha.. just to add, sister is 3 years my senior and absolutely nuts ha ha.. we’ve all been curious teenagers haven’t we?.. I’m sure you’ll be able to implement your imagination and find a way of sorting yourself on the hush.. really isn’t necessary to inform your brother