Yell louder, or Better yet just full on scream.

Was he orange with fake yellow hair?

Just goes to show women aren't the only one who deal with things like this.

Elderly pull that shit, and they get away with it on grounds that they're old.

just say he is touching your crotch

whoever said that ydi, ur assholes.

next time whisper "Take it out" and then scream

Maybe they were filming a Japanese porn movie.

I would have definitely tried to make a bigger deal out of it OP. You gotta stand up for yourself and show that creep that he doesn't get a pass for being an OLD creep.

Kept grabbing? How many times does he have to grab your brother before you so something about it? I would have pushed him away and make a huge scene about it after the first time.