“Metta?”
“Mm?”
“Can I uh, get you off?” You ask timidly. Mettaton smiles, wide and genuine as he moves to take his heart out of the container where his stomach should be. He hands it to you and you gently place into both of your palms.
“Go wild, darling.”
You oblige as you all but shove your face into the reddish-pink heart, alternating between nuzzling it and sucking every drop of cherry flavored goop from his heart. Your face is dripping with the warm gel, it's starting to drip down your neck, and you're pretty sure you're in heaven as you feel some drip off your and land heavily on your over sensitive clit.
“Ah! D-arling! Please! I-I-can’t take it!” Mettaton pants. You take this as one part challenge, one part revenge. The heart is malleable, and if you're slow and gentle enough, you can slide your fingers into it. Which is exactly what you do. You're about two knuckles deep before you start flexing and crooking your fingers inside the heart, still absolutely eating him out with all the energy your post-vibrator body can muster.
“Ah! Uh- Ah! Ah-ahh! D-ARLING!” Mettaton shrieks. You giggle and keep giving his heart little kitten licks until his moans turn to little glitchy pants.
Feeling significantly more stable, you crawl over to the bench Mettaton is laying on and slide his heart back into its container, but not before roughly squeezing it one last time, reveling in the return of the glitch-laden screaming.
Mettaton is twitching violently, and you laugh at the static pops that have replaced most of his moaning and panting. You end up manually wrapping his arm around you and you sit beside the bench, occasionally nuzzling into his neck as you wait for him to stop overloading.
Eventually, he manages to calm down, though his fans are still whirring so fast you're a bit unsure if he's not literally melting.smirk plastered on his face.