Both my boys were like that and while it's very cute for them to be a Mummy's boy it can be damn stressful as well. Sorry I don't have any answers for you.......I just waited it out...... I didn't know what to do either.

Is it a concern for you to put him to sleep yourself? If it's not a concern, let Daddy be for play time and Mummy be for comfort and sleep time.  I put my baby to sleep every time no matter who was around to do it for me.  It was our special wind-down time together and I stayed with her until she went to sleep.  She never did have a daytime nap.  Briefly when she was about 11 months old for about a week she was having a half hour daytime nap but that was it.  Maybe just go along with his cues.  Worked for me.  No need to be pushy and force him into conforming to any views of people who have never met him before.  Why use a text book to raise your baby?  Does he have to let his Daddy put him to sleep?  Just ask yourself some questions before deciding the best course of action.  Good luck.

Yes, it does sound like he thinks daddy is for play. Your son just has to learn that nap time is nap time, no matter who puts him down. Have your partner continue to put him down but do not intervene yourself. Your son has learnt that if he cries, mummy will come running, which I'm sure you don't want. Your son learnt to nap when you put him down, is there something you did that your partner can do? Such as controlled crying? Once he learns that crying will not bring mummy in, he will stop. Don't get upset over it yourself, it's just a part of your little one's learning.

the first thing that springs to mind (you probably thought of it already) is that DS thinks that daddy is for play and you are for sleep! Daddy will have to practicr being boring somehow! All I can think of is either to persist and wait for the penny to drop, while strengthening his sleep cues (dummy, blanket, quiet music, darkened room, sleepy words eg "night night"), and reassure daddy its coz he's too much fun not coz he's a bad dad, or stick to you putting him down for naps til he's a little older then try daddy again. Whatever suits the 3 of you best.

but i expect others have some good ideas too, so keep checking!

ps sorry for one-handed typing, teething baby in other one!