My female cousin and I would 'experiment' up in the bedroom whenever we visited, and were left home alone while our parents went to the pub.....we were both teenagers, and she was the same age as me.....she had lovely big boobs for her age, and she would tease and flirt, making me hard, and encouraged me to pull my erect penis out to 'show her' and I would masturbate in front of her as she lifted her top and pulled her bra down to show me her bare boobs.....she would let me have a feel of them, and then asked me to suck on them, and to my delight and surprise she gave me my first hand job.....we did progress over time too....