Boyfriend telling lies.....again?

My boyfriend and I have been together for 2 years and recently moved in together. During the first year, we had a lot of problems with trust. He often gave his number out to girls that he met, which eventually led to him cheating. After we moved past the cheating, I asked that he stopped giving his number out to girls because I wasn't comfortable with it and I was afraid it would happen all over again. The past year has been good, and we even moved in together, but now I've found out that he's been giving his number out again. He gets texts and calls from girls in his classes and from work that he's exchanged numbers with, and when I ask about it, he lies and says that he doesn't know how they got his number.

I guess I just want to know if it was reasonable to ask him not to give his number out, or if that's taking it too far. And if so...is him lying to cover it up just not wanting me to get mad or is the past coming back again?