Mahirap talaga yun. As a Scorpio guy we don't forget betrayals like that, once I feel the girl is being dishonest with me eh wala ng 2nd chance.
I don't know if you're talking about simple white lies or cheating pero if you are talking about the latter, I am under the belief that once a girl cheats, she will cheat again if given the chance and timing so I would say in any situations like that, drop the relationship like a hot potato cause in the end ikaw lang ang mag suffer, dami naman trust worthy jan.
Actually not only when she cheats on you, but if she had a history of cheating with ex's, that's a huge red flag for me.
If simple white lies lang naman, perhaps take the time to also understand ano kaya dahilan for that, perhaps you have an explosive tempter and can become very irrational or something, but then again I'm talking about simple lies na although hindi tama eh hindi naman ganoon kabigat for you to pass judgement that a relationship with this person is just not possible. Gauge mo rin, pero personally ayaw ko ng sinungaling.
And a note, sometimes yung mga seloso won't accept the fact that they are, so isipin mo din if your suspicions are well justified or you're simply making monsters inside your head.