He totally did XD
If i understood, he thinks that her love for him is sooooo deep and powerful that she will accept and do anything to make the most important person in his life, aka his son, happy. Going so far as '' loving him'' during 5years and showering his son in presents, without waiting for anything in return. In his head is like '' oh dear i'm a jerk cause even if i love her and have a child with her, her blood will never inherit the family '' like it's the mistress blood that will. Moreover the gossip she will bear, her position which will be weaker aaaaand so on. So he's like i'll give you everything you want as long as you can bear everything that i'll will not concede.
Sooooo all in short he pities her, and he's in awe in front of her '' strong love'' and selflessness. You suffer cause of me, but that's sooo charming so i' ll love you more. Making everything so funny because she doesn't give a damn about him
That's my understanding... It can be wrong XD
i think my English has became dull.. just what happened? did he just misunderstanding again or wha? Σ(っ°Д °;)っ