Iam a scorpio girl as well, iam not as familiar with libras to give much advice with that particular guy. However without even knowing their signs i can say this…….most times (ive been here done this too) we like the more exciting guy (in this case seems to be the aries) rather than the “good guy” (libra in this case). We scorpios are usually attracted to the one that has more going on anyways (not always the case but most times it seems to be), the one that causes our emotions to run wild and of course not understanding him (aries) completely may draw you to him as well. Being a scorpio you are able to feel either of these guys out pretty well as far as whether you could trust them with your heart. Its obvious at this point you can’t trust this particular aries guy (not saying all aries, but this one), and more than likely your able to trust the libra more so (in this situation, again not saying anything about libras and aries in general). In all honesty what i think you should do, now again being a scorpio im sure you have your ways of drawing this aries guy in, however i believe this particular guy (again not all aries men, just this one) will continue to do what he is doing. I don’t believe he will ever truly keep you happy. And the libra may not either if he is your “back up” plan. If hes not the back up plan then i say go for the libra and run like hell from the other lol. If he is the back up plan, i say get rid of both (again not having anything to due with their signs, just feeling out your reflections on two men) and find someone new. Hope this helps:)