Mumbo being a vampire in season 11, except its completely new to him. He doesn't know how to be a vampire, he knows that he needs blood to live, but he's a horrible hunter and is quite hungry for the early part of the season. Tango takes note of this, he isn't afraid to take Mumbo in as a fledgling, teach him the ways of being a vampire. Hell, he doesn't even care that Mumbo makes friends and gets distracted during hunts.. Maybe that's a lie actually.
A lot of Tango's attention is focused on Decked Out, he's building a dungeon that is living and breathing practically, it takes a lot of time and effort. He's collected quite a few vexes, but he's noticed their numbers slowly dwindling and he began hearing more complaints of random vexes flying around the server. Somehow, they slipped out and escaped to attack other hermits. In the wake of that, they had left abandoned nests filled with round, translucent silvery blue eggs.
Incubating Vex eggs was difficult, they were temperamental. But it would be easier to hatch Vexes then try to wrangle a bunch back into containment. And, well. Vampires had the perfect low body heat range for these sorts of eggs. And he just so happened to have a fledgling vampire running around who wanted to please him so much.
It doesn't take much convincing, either.
He's easily able to get Mumbo back to his base, legs spread and pussy exposed. The eggs aren't that big, maybe the size of marbles. But he has a lot he needs incubated. Tango is easily able to press them into Mumbo, watching him whimper and shift as they settle inside him. Tango could easily do a few at a time, but he draws it out, slipping his fingers in as well and pushing the eggs deeper.
Tango makes sure to reward Mumbo a few times as well, shoving his fingers into Mumbo to make sure the eggs don't move and stroking Mumbo's t-dick until he's actually crying, tears clinging to his eyelashes. He's too full, a clear bulge in his tummy where the eggs are. When he thinks he's finally done, practically filled to the brim, Tango guides his dick to Mumbo's entrance.
He's so sweet to Mumbo, kissing him as he gently rocks his hips. Mumbo didn't even think the eggs could get any deeper into him. Tango fucks him very slowly, nipping at his throat and trailing his tongue over the little marks he leaves. He pulls out suddenly, finishing on Mumbo's stomach. As much as he wants to breed Mumbo properly, he doubted Mumbo would be happy with him. Even though Mumbo complains when Tango puts a plug in him, Tango just shushes him and says its necessary.
And well, maybe its a little bonus that Mumbo really doesn't want to move around for the days following. Tango gets Mumbo all to himself.