Why do you think the Roman solider keeps coming around?

When he accepted Simon's offer to work in his shop, Daniel had to agree to one important condition: he must repair any items brought into the shop by Romans. Simon's rationale is that refusing to do so could lead to trouble in town; lives may be lost. Daniel reluctantly accepts Simon's condition. He hates the Romans with a passion, having fought so hard against them. He does not want the Romans to be anywhere near Judea, let alone Simon's forge, but he is sensible enough to accept Simon's point. A zealot he may be, but a complete fanatic he is not; there are potentially lives at stake here.
One day, a Roman legionary by the name of Marcus comes into the forge needing a broken bridle ring to be fixed. Mindful of Simon's instructions, Daniel grudgingly agrees to accede to the Roman's request. But nothing can change how Daniel feels about his people's oppressors. He is still dedicated to driving every last Roman from his homeland and continues to engage in clandestine resistance activity. (Though as he will later discover, Marcus is a German, not a Roman). Not surprisingly, Daniel needs to be careful that Marcus does not suspect what he is up to. He soon gets paranoid, finding it suspicious that the legionary always seems to show up on the same day that Daniel holds meetings with his revolutionary group. There is a danger that Daniel and his fellow zealots are being spied on.
However, Marcus's regular visits to the shop have nothing to do with counterrevolutionary espionage; he is falling for Daniel's sister, Leah. Although this means that Daniel has less reason to feel so nervous about being spied on, he is still not exactly thrilled that one of the hated enemy is wooing his own sister. Daniel has never accepted Romans—or the non-Romans like Marcus who fight with them—as fully human. He has always looked at them as the enemy, the other, the forces of occupation ruthlessly exploiting his sacred homeland. The very idea that his own flesh and blood could become the object of affection of one of Judea's hateful oppressors is simply too horrible to contemplate.