If he wants you to go do better, then he should be happy for you to go now when you have the opportunity. I would tell him about it and I'm sure he will have a

If he wants you to go do better, then he should be happy for you to go now when you have the opportunity. I would tell him about it and I'm sure he will have a favorable response. Help him make a good transition and find someone to replace you. Oh and it's non of the other company's business what you say between you and your friend. Don't tell them anything about it, it's not ok for them to even ask.