It is possible that this lifestyle he is sharing with you have just made him more comfortable in exploring more of his own fantasies. Opening up a completely new door with your SO and only seeing positive benefits might have made him more open to even more possibilities that he hadn't really considered before.
It is also possible that he is a switch, it's not really uncommon, and some people wanna go between being the dom and the sub.
I would sit down for atleast 2 long talks with him, in a non judgemental way, there are so many possibilities as to what is on his mind.
Make sure you have 2 different talks, one when he is horny, and one when he is completely sexually satisfied, the different ideas you get depending on your sexual state of excitement can really play tricks on your mind. Keep in mind that his might be new ideas for him, so you gotta be open to these ideas changing over time, he might completely lose interest in them, but they might also be more and more enticing to him, and everything else in between.
It is also possible that he is a switch, it's not really uncommon, and some people wanna go between being the dom and the sub.
I would sit down for atleast 2 long talks with him, in a non judgemental way, there are so many possibilities as to what is on his mind.
Make sure you have 2 different talks, one when he is horny, and one when he is completely sexually satisfied, the different ideas you get depending on your sexual state of excitement can really play tricks on your mind. Keep in mind that his might be new ideas for him, so you gotta be open to these ideas changing over time, he might completely lose interest in them, but they might also be more and more enticing to him, and everything else in between.