The first secret Ted keeps is that Blake’s been using again and that he needs more help than he can give him. He keeps that one from himself.
The second is that he thinks so little of himself, he’s willing to steal money from a child to numb away reality with a drug he lies to himself won’t hurt him. He keeps that one from Emmett.
The third is that there’s a jeweler’s box hidden in his pocket (it’s Blake’s fifth anniversary of sobriety today). That one he keeps from the man who’ll say yes in just a few minutes.