The phrase "young stallion" often refers to a young man who is strong, confident, and full of energy. It can liken someone to a powerful young male horse. Full definition
His sire, Speedy Scot, won the 1963 Hambletonian for the esteemed Castleton Farm and is a most promising young stallion. (si.com)
Shortly after Ransom began following High Tail and Sam's band, he noticed a second young stallion hanging around a short distance away. (scientificamerican.com)
i am a 19 year old young stallion, who's 5» 10» in shape and news some mile teaching to show me how to treat a woman right. (meetlocalmilfs.com)