My husband accused me of cheating

I've never in my life cheated on him. Ever. But just because I took the iMessage from my phone off the iPad he thinks I'm cheating on him. I added an old friend that he used to hate on fb again a couple months ago because i thought he had gotten over himself and realized there's NOTHING GOING ON. my husband has cheated on me multiple times when we were only dating. He brought this up at the dinner table on date night tonight. I couldn't even eat I got so upset. Help....