Assuming you do have attraction for women (romantic and physical), you would still be heterosexual. You're just a heterosexual person who can still enjoy the strictly sexual pleasures to be had from a good penis. What you describe is known as MSM (men who have sex with men), which means, as I just described, men who enjoy the strictly sexual pleasures shared with other men, despite feeling zero actual attraction to them and having no desire to be romantically involved. (The opposite is WSW, women who have sex with women.) Usually I wouldn't say someone falls under that category after a single instance of sex because that would typically be bi-curious experimentation, but since you liked it so much and presumably would do it again, you can probably consider yourself MSM.
However, why worry about labels? So you tried another form of sex and found you loved it. Great! Just enjoy it without being concerned with labels. All you have to do is make sure that (1) you're always safe when it comes to sexual health and STD prevention (a human concern, not just a gay concern), and (2) whoever of the same sex you plan to share sex with knows that you have no attraction for guys and no interest in a relationship beyond simple platonic friendship, and that the sex is just for mutual pleasure and fun.