He sounds like a normal curious 11 year old that's just starting puberty and I would say probably in the next few months he will start to grow a few strands of pubic hair around the base of his penis and on his scrotum, as he enters more into puberty he will notice his penis will start to fill out more his festivals will swell more and his scrotum will hang lower and it's perfectly normal for one testicle to hang lower than the other, at what age did you first notice his penis was abnormally long?