By drugging Ultraboy into fucking her.

Dr Bluder smiled as her guards wheeled Ultraboy down to the evil doctors office, hurrying along from the impregnated Ultramom, Dr Bluder went to her **** cabinet, quickly finding the ones she was looking for.

As she arrived in the room, her guards were just finishing strapping Ultraboy to Dr Bluders magnificent four poster bed, each of his limbs anchored to one of the four posts. As she approached, Dr Bluder smiled as she prepped the needle with the **** to make her prey compliant. Ultraboy struggled with his bonds, trying to avoid whatever **** the evil doctor was going to pump him with this time, but it was all to no avail as she quickly applied the tourniquet and found his vein. Ultraboy had no chance to resist as the **** quickly surged through his system.

Ultraboy writhed as the **** got to his brain. Meanwhile, Doctor Bluder injected herself with the other ****.

"My horny little superhero, the **** you've just received has made you utterly compliant to me, so, a test. When I ask you, you will tell me if you desire me. Well, do you?"

"Y-yesssss......"

"The **** I've just taken was a fertility ****, I'm at peak fertility right now!"

Ultraboy thought back to all the times he'd jerked off at the thought of any supervillainess having her way with him. He looked down his body to see Dr Bluder slowly and seductively stripping off.

"W-what are you going to do with me?"

"Well, after watching you and your mom fuck each other's brains out, I got horny and broody, you see Ultraboy, your cum gave your mom triplets!"

Ultraboy groaned at the news that the evil doctors plan had worked, but he had no time to truly process the fact that he'd just impregnated his mom with his own siblings because Dr Bluder was slinking across the bed towards him, despite the fact that she was an evil villain, he couldn't help but notice the swaying of her perky tits as she got closer to him.