Can someone give me an opinion on this please?

Before I started seeing my present boyfriend I was on a language site doing modules etc, and you set up a profile on there so people can see what country you are from and then they send you their completed work for you to mark. Now long story short, there was this guy on there who I was just friends with and marking his work etc. Then I gave him my email if he needed help. Now he was just a friend nothing more. He lived in a different country initially, then came to London as a student. He asked if he could see me etc I said no. I told my boyfriend about him but the only problem is I told me boyfriend I had actually seen him (when I hadn't) I didn't tell him I met this guy through this language site. Rather I said I met him through this language event. Anyway, not because I was hiding anything but simply because I wanted to me him jealous a bit (this was at the beginning of our relationship) and I was just testing him a bit. Now we've both forgotten about this person etc, because at the end of the day he knew about him. But we've had arguments over this stupid site and I don't know whether I should tell him I met this other guy there or just let it go. Because if I do tell him I told him things differently, he probably won't trust me again. So please?