Should i give a liar that i love another chance?

He is lying and making excuses. Doubtful he will stop. Hopefully since you both live in your parents home, you are not sharing a room. Don't force him out, just distance yourself. Keep cool but limit interaction. Don't confront him, but if he asks don't lie either. Tell him what you know. And that he needs to rethink the relationship. After all you both were quite young when you met, and now have matured. Things change over time.