View attachment 1512384
You're missing a detail. In the photo, not only Jade and Steven, but also Tybalt. According DPC, family of Burkes should mark the problems and unite all the points.
Jade - if you're Dik and on Sage's way.
Tybalt - if you're in the way of Jill
Stephen - if you're in the way of Bella (he molested her in the episode), Josie and Maya.
In any case, the reaction is understandable. He saw Mona run away from Burke at the party, saw his pants in the glory hole. He can add two plus two even though we are not explicitly told about it.