Same. But hopefully we get more of a reaction next chapter?
I think it's because he didn't expect Taemin to confess his feelings. I'm sure we are going to see a tender gentle Woojin in next chapter.
And also I'm looking forward to see how he will crush the bugs who want to part them away because they have to be eliminated (his own words chap31)
His reaction was exactly what I expected. He knew from the beginning that it was Yoon Taemin in front of him, and was only waiting for the time when Taemin confirmed it. So Taemin confirmed something he already knew, and would not be fazed about. But next chapter, things would probably be laid out on the table.
Chap 50 : Am I the only one being a liiiiiiittle bit dissapointed ? I mean, Taemin cried so much and Woojin was so inexpressive, WTF !!! Finally, Taemin told the truth and when you saw Woojin ... nothing :/ I was expecting so much more ...