A Quick Guide to Nice Guy(TM) Responses (aka You Can't Win):
Act friendly "She lead me on! Bitch!"
Don't act friendly "She didn't give me a chance! Bitch!"
Let them down nicely "Well she said 'not right now', so I'll keep trying 'til she changes her mind."
Flat-out say no "What?! But I'm so nice! What a bitch! I'll keep trying 'til she changes her mind because she OWES me now."
Date someone else "Ugh, women only date jerks!"
Don't date someone else "Hello?! You clearly are single and so am I, why aren't we naked yet?"
Marry someone else, have baby, die tragically fighting Voldemort "Now I will torture her emotionally and physically abused son because I loved her so much and she married that jackass Potter instead!"