A tootie pie is a cute name for a girl who loves giving rimjobs, eating ass and sometimes engaging in either light or heavy scat. Similar to how the term barf babe is a cute name for women into puke
"Dude I took my gf Heather home last night turns out she's a total tootie pie." "Oh shit how deep did she go?" "Well I couldn't kiss her after and I had to get her some mouthwash."