Does "se" and "o" always stick together? So if se is in the sentence, so should o be?
No, they have their own purpose in the sentence. Here the se is part of the verb "zajímat se". Did you read the Tips and notes?
"Zajímá Tě ten muž" is a correct answer and shall be accepted. Thank you.
There are many accepted forms and this one was missing, added.
Mathias1005, has a great question. The hint didn't have "o" as a hint, but yet, again, when i didn't include it in my answer, my snswer is incorrect.... Losing these hearts are maker in this free app not nearly as fun as it was.