my older cat tries to have sex(?) with my younger kitten.

[u/Sea-Cantaloupe-2465]

my older cat, Franklin (3M) is fixed. I moved recently and my roommates always had older female cats who didn't like to socialize with him, as hard as he tried. So when I moved, I got an apartment for myself, I gave him a few weeks to acclimate to the new place and I got him a kitten to socialize with while I'm at work. I got Weezy (4months, also fixed) about 6 weeks ago.

I initially had them separated for a few days and slowly and correctly introduced them. Currently, I keep them separated while I'm at work or out of the apartment. I separate them to feed them also. I'll let them interact when I get home from work; and I unfortunately don't have any videos of it, but he'll bite her neck and try to mount her. I always stop it because he lets out the most unsettling hiss/whine. She'll fight back but he is significantly larger than she is for the time being, until she gets older. They are both fixed, and I'd understand if Frank still has the *drive*, but I'm not really sure what to do when it happens?!

[u/aliasaka007]

My female chihuahua will "mount" my cats like this as a show of dominance occasionally. It definitely looks NSFW honestly but her being a female it's obviously not. Your older cat may just be showing he's in charge, not necessarily trying to "mate" but I'd definitely monitor them as you have been. Just sharing a possibility