Did you say, "I was not intimate with my ex"? Talking about one's past in dribs and drabs is not lying about it. Relationships take a long time to develop and overdoing the who-I-use-to-be-before-you talk can easily overwhelm another person and the gradual growth of the new relationship. Just because the old relationship did not get enough sun and ended up moldy :-) does not mean you want to stick the new plant out in the sun with insufficient water?

If you did lie, said something like, "we only kissed and nothing more happened", any male should be suspicious of that, knowing themselves and follow that up, ". . .and he was okay with that?" or, "I don't understand how that could continue". That your boyfriend wanted to believe your "lie" and is now upset about the whole picture; it is your life, your past, it's over and done with but sounds like you all have communication issues of your own, now, worse than any other issues. Don't let him get away with a double standard; if he has been intimate, he has to consider it both ways and square it in his own mind. If he has not been intimate, it could be the age difference, maturity, and experiences are not insignificant.