Letting My Boyfriend Sleep With Someone Else?

So I took my boyfriends virginity and so I guess my biggest fear in our relationship is that he'll get bored or curious about other women. The other night we were talking about it and he said as of now he has no interest in other people, but I told him that sometime down the road if he feels the need to be with someone else, since I'm the only one, then I will let him be with one other person of my choosing, of course they have to get tested first because I don't want him coming back and giving me something or getting something for that matter, but it is wrong or weird at all that I'm giving that option to him? I know I'll get at least a little jealous, but I feel better about it because it'll be on my terms and I feel that it's much better than him cheating on me somewhere in the future. At the same time though, does that open a window for him to want more?