its no different in reverse
if a 15 year old girl sees a man with muscles and is big..not lean twinkie type but real beefcake..she will think he is gross
fast foward to when she is 25, her poossnot will moisten at the sight of thick pecs and a set of killer arms
actually young teen girls love muscular men, and 25 year olds are allready matured up and only appreciate good looks but are interested more in mens profession and quality of life.
or do you mean that teen girls like twink muscular physiques in men and 25 year olds love the bigger type muscularity?