I literally just wrote this RIGHT as I got up this morning. (4 am kill me) this will probably not make sense.
As much as I would love to see Homelander come heh apart during sex, I think that him being introduced to the most simplest concept of skinship or experiencing intimate things that doesn't lead to hard core pound town would have the same devastating impact on him.
Like, ok bare with me and my sleep addled nonsense brain but I would like to just start off with just having him experience some cuddles. Maybe it's early in the relationship (firm believer he is demisexual like me!) and you guys are still getting to know each other and you notice how tired he is viscerally even if he is still plastering that smiley persona. So you offer your lap to rest his head and maybe watch a movie. He might be weary at first but when you start absentmindedly carding your fingers through his hair? Oh man. Everyone KNOWS how that man would melt. Madelyn knew what she was doing with this starved boy.
Next would be a little spicier and—more importantly—fun! I want that man to experience what I call "teenager moments" like pulling him into an empty room just to make out or sneak around maybe into restricted areas for more cuddles and kisses because you know he gets stressed and it's fun to see what you guys can get away with.
Now this is (personally for me) the most important part for him. As I mentioned above, I think skinship for this broken and insecure man would do wonders. The trust in you for him to even consider taking off the top of his suit let alone all of it at the same time would have to be deep.
I think the biggest thing he is sensitive about is his body image. I'd suggest little touches to his neck and maybe sliding your fingers a little under the sleeves of his suit to caress the skin of his wrists and (if you can) forearms bit by bit to get him used to having not only the feeling of other parts of him being touched but to know that you WANT to explore other parts of him. That you are not just there for self satisfaction and want to make HIM feel good. You want to feel his warm flesh under your hands —the beat of his heart, not the pads of the faux muscle that Vaught wants people to think he has.
This is that part where you would combine the intimacy of making out and cuddles with the extra step of removing an article of clothing. He would feel much better when you also remove your clothing. He hates feeling vulnerable.
With Vought shoving unrealistic media and propaganda down his throat since infancy, Homelander would immediately think naked = sex but you would have to convince him that you are not expecting sex. You have to show him that just feeling the skin of your partner against yours can be just as intimate.
You could be in his lap or vice versa and he would marvel in the sensation of having your chest pressed against his with no thickly padded barrier. Moaning into your mouth as you slid your hands down his shoulders and back.
This would be so cathartic for him. He was always expected to give and provide and act a certain way but with just the two of you sitting on the couch or bed, caressing each others skin. Finding small things like his ribs being sensitive or just enjoying the warmth and scent of your naked skin. He doesn't have to worry about fulling expectations. You love him.
Expect tears and sad little whimpers. This man needs a full blown naked cuddle session.
Sorry if this is just random ranting that makes no sense. I had to get this out or I would be consumed.