An extremely ecstatic/happy/attractive/social description for a person. Someone who is extremely happy, has a lot of friends, is very attractive, or just enjoyable to be around
Man, that guy is so damn excited, she's like Shelbi Mullen excited!
Holy crap that girl is HOT, she's freaking Shelbi Mullen hot!
Hey, I like your friend, she's very Shelbi Mullen-like
A tackle of love, a very pleasant hug or intercourse
Guy 1: uhh, why is that girl running straight at me?!
Guy 2: She's got her arms open and a big smile on her face... You're about to get merped, bro!
Girl 1: Hey best friend!
Girl 2: Hey!
Girl 1: Merp!
Girl: So I was with my boyfriend, making out and stuff, and one thing led to another and we eventually... you know... merped