Am I selfish?

So, I've been with my boyfriend for a while now. Our relationship has been great, no issues, we get along soooo well. Now, the problem isn't with my boyfriend, but rather our mothers. They are always getting in our business, the other day my mom asked me if we had our first argument yet, and was teasing me and was actually getting upset when I wouldn't tell her. I don't understand why she was asking either because she was asking it as if we had just gotten together but we've been together for a while now. Anyways, he is going to propose soon. My mom keeps on messaging him asking him how he's going to do it, and his mom got mad at him when he said he wanted the proposal to be private. I WANT it to be private, it's our relationship and not everyone else's. I just wish they would stop poking and prodding through our business. But is it selfish of me to want a private proposal? I do not want anyone there. Especially our mothers, as they will make it about them and we won't get to enjoy the moment ourselves.