So since you tell us that at the moment you are also interested about
a different guy, you used to be together in the past why did you ask if he will marry the girl is being seeing right now instead of asking if he is still interested(has feelings etc) to you? if you are going to be together again or something like that?
even if we tell you that he's not going to be with his current girlfriend in the future how this helps you?
My point is: he may end this relationship for various reasons but still not interested to you...he may find someone else..or just be single...etc.On the other hand a person can be also in a committed relationship and for various reasons have feelings and interest for someone else.
You see once more instead of asking a clear question whether this person has romantic interest for you, or if you are going to be together again... you asked if he loves his current gf and if he will marry her
To sum up..asking questions this way won't answer your actual question..which presumably is whether you'll be together again .
And please start reading as to understand the basics.There are plenty of online free sources like
http://www.skyscript.co.uk/horary_intro.html
and books of course as Lilly's Christian astrology or Frawley's real astrology, horary textbook...etc