Hmm..does bathing together consider?
I had few cousin though... and often bath with them since young... 2 female cousin was elder cousin though, and one of them treat me really nice since young... I bath with this 2 cousin, and my male cousin (their youngest bro) till quite old (About 14-15)... and after that, only bath and 'play' with my eldest cousin (the one who treat me really nice) till about 22 or so...