Because he doesn't remember the night and the Duke said he had talked and confessed to him that night, also he thinks the Prince doesn't like him, so in his head the father and the person he slept with is the Duke
Still i think it's a accelerated generalization and as a detective he should know that very well(▰˘◡˘▰)
Ahhhhh just accept it louis maetel is the father ╥﹏╥
I mean, If you for drunk and slept with someone that you don't remember, discovered that you were pregnant but the only 2 man in the part were one who claimed you two talked and he confessed his feelings to you but you never replied and one who always looked like he hated you, who would think is the baby daddy? Specially when it was 4 months after the part and one was ignoring you entirely but in your memory the person said to contact them and the other actually wanted to see you and asks why you didn't contact him when you meet?
It kinda makes sense, but yeah, I can't wait for him to discover that Maetel is the baby daddy and that he has fockin red heair wig, bitch is probably jealous of Sabrina's hair lmao. (≧∀≦)
I cant understand louis why does he persist in the idea of wayton being the father