boy

adolescent, juvenile, kid, kiddie (also kiddy), kiddo, minor, moppet, teenager, tween, youngling, youngster

brat, gamin, guttersnipe, imp, squirt, urchin, whippersnapper

schoolboy

toddler, tot, tyke (also tike)

admirer, crush, steady

suitor, wooer

beloved, darling, dear, favorite, flame, honey, love, lover, significant other, soul mate, squeeze [slang], sweet, sweetheart, sweetie, sweetie pie, valentine

fancy man, gigolo

date, escort

groom, husband

fiancé, intended