Kristen,
My cat Squeak likes attention on her terms. Bernie loves attention all the time. There are many times when Squeak decides it's her turn & she'll lay on the bed or find us & lay on the floor (which means come pet me). When we start to Pet her Bernie will sometimes Jump in between. When he does that HE gets in trouble. We yell NO, & he looks a little disappointed but Squeak stays there. Now when we didn't yell @ him she would run off and hide & it wasn't fair to her! Now he knows when it's her time he can wait his turn. Yes, he still will try to attack but we watch out for him & don't let him do that. Since then she seems more tolerant of the things he does.

You might want to try telling Lilly NO when Luna is in your lap. 10 minutes of Luna seeing you tell Lilly no may help.