I'm mgtow in the sense that I don't believe in love and relationships etc.

I still hook up with quite a few girls and there's one coming over in literally 4 hours to see me, I have just found out that she has a boyfriend since 6 years, she never mentioned him to me before, I've hooked up with her before but this whole thing puts me in a bit of a moral dilemma, I'm not sure if I should just go ahead and not give a fuck...or if I should cancel...but then again the thought comes to me "fuck that guy, it's not my problem, would any other guy have been as considerate with me? I doubt it."

What do you guys reckon I should do?