Bounce in this context is very colloquial, so the way it's phrased is not 'normal' English. But there are similar phrases which have the same format and similar meaning in English, such as 'Their Dad ran out on them.' (Their Dad left/abandoned them), 'I skipped town on them.' (I left the town they were in), 'My Mum snuck out on us to go to a party!' (My Mum left without telling us to go to a Party) The implication here is that the person leaving has made a choice, but the people he/she has left are passive, because they are being left behind. If I had to guess at exactly why ON is used in these phrases, I'd say it's because when something is Over/On/Above etc. something that usually implies height, or superiority, so by doing certain things ON someone, rather than TO/AT someone it makes the subject of the sentence seem more powerful than the objects, rather than equal.

bounced on them is poor English slang not worth learning. but it means I left them. when you bounce a ball "on" a wall . same way can not use "left" as it would not make sense

hi! i totally agree in your question , however in this context i suppose the right expression is "I bounce up on them" which means, Someone was enjoy the conversation and felt willing or temptation jump on the person because realized to be the right person, so, in this case, “bounce up on” might suit. to "bounce up on it" means that you find a certain person physically attractive and would enjoy having intercourse with them. D AMN!?!? that guy is so sexy, I'd bounce up on it"