Person who makes love for amusement without serious intentions

One word substitute is Philanderer.

Concubine: (in polygamous societies) a woman who lives with a man but has lower status than his wife or wives.
Philanderer: a man who readily or frequently enters into casual sexual relationships with women; a womanizer.
Dandy: a man unduly concerned with looking stylish and fashionable.
Flirt: behave as though sexually attracted to someone, but playfully rather than with serious intentions.