Yeah, I wondered whether you might be a bit too interesting as well
Would you be comfortable with ignoring him or refusing him if he wanted more cuddles/stories/songs after the planned x-minute bedtime routine was over?
What I was thinking was, perhaps you have 2 stories, then a song then it is time to lie very quiet and very still. (This is what I tell Natty when she tells me she doesn't like to sleep. "Just lie still, and very quietly then.") Initially of course he would probably struggle with it, might cry, might try to distract you etc. But if you are consistent and respond with, "time to lie still and quietly" or some such calm response and demonstrate it yourself, he may get bored of it and wind down that way?
Other thing that might work is to have you and your DH lie with him. You and DH get some quiet, close time (even though your DS is there) and you both demonstrate how to relax. Then, if you fall asleep, you'll have DH to wake you up once DS is asleep, or he may even fall asleep with you which is kinda lovely too
Natty has never 'allowed' DH to put her to bed either. I was worried about it before Phoebe came along but TBH it worked out fine. DH would have quiet cuddles with P while I put N to bed, then I would feed P to sleep a little later. P fed to sleep until she was about 13mo, but now quite happily lets DH put her to bed. It can still work out, so try not to panic