HiCustomer Thank you for asking your question on JustAnswer. By the way, it would help us to know:
-What are your ages?
-How long have you been dating?
-What did you lie about?
-Could you explain your situation a little more?Thank you again for trusting us with your problem. Please reply as soon as possible so that we can finish answering your question.
It's more of her being hurt that you felt the need to lie to her after she has asked you to be honest. It's going to take some time for her to trust what you say now and now it has carried on to her not being able to trust you around her roommate I don't think she feels as though you have cheated with her roommate I think she feels that if she cannot trust you with telling her to truth about the pipe then what else would you lie about, you are going to have to spend all of your free time making her trust you again which means telling her the truth ALWAYS even when you think she will get upset with you be honest is much better than not being trust and her questions your motives whether good or bad. Don't leave if you love her stay and work it out make her a special dinner or take her to dinner and talk about everything tell her why you didn't tell her in the first place and tell her you would never want to purposely hurt her this way and you will do whatever it takes to make things the way it was. You have to have your action match your words which means don't say one thing and do the exact opposite.
Allow her to be upset and angry if that is what she has to do to work through this but you have to be able to talk this through instead of living in silence while you are there don't use this time you have together being mad at each other, you never know when it's your last time together so live your life that way. Take her to a romantic restaurant for the two of you and talk about this even if you're doing all the talking and she doesn't say anything if you are one on one she will hear what you are saying even if she acts as if she isn't. Tell her how much you care about her and that you want this to work and you don't want to lose her. Make sure you are okay with each other and at least communicating before you leave to visit friends and your mother, you don't want to go there on awkward terms and ignoring each other.