Homelander's relationship with Madelyn Stillwell is one of the most f*cked up dynamics in the series. She's the only figure of authority he listens to and yet he doesn't truly respect her. Beyond this, their weird mother/son/lovers thing is enough to prove that there's clearly something off about Homelander in general. He's also immensely jealous of her baby which is wild, because there's a possibility he's actually the father.
How he murdered Madelyn is cold. Just as she thinks she's about to be saved, he literally melts her eyes out of their sockets . . . all because she lies to him about the whereabouts of Becca and his son. If this shows anything, it's not to lie to Homelander.