nice guy

noun2

1. •
   (euphemistic) An inoffensive adult male who desires romantic companionship but who is too bland and uninspiring to be attractive.

   • "My frustrations were pretty typical Nice Guy relationship issues," he says. "Not feeling appreciated, not feeling sexually desired by my wife. I didn't feel like...I received as much as I gave." — 2002
2. •
   (Internet, disapproving) A man who pretends to be kind and polite with the goal of attracting women, often becoming hostile and misogynistic when their advances are rebuffed; someone affected by nice guy syndrome.

   • Plenty of men will treat women kindly, but Nice Guys like to think that behaving kindly earns them a gold star. It doesn't. — 2016