So we know
1) Spock and Michael didn't get along at first.
2) Then they got along too well
3) During this period where they got along too well something happened that caused them to stop seeing each other anymore, which Michael feels guilty over.
Since this is TV and Michael was fostered with him, not his biological sister, I'm pretty sure they had sex. Let's see what the general opinion is!
1) Spock and Michael didn't get along at first.
2) Then they got along too well
3) During this period where they got along too well something happened that caused them to stop seeing each other anymore, which Michael feels guilty over.
Since this is TV and Michael was fostered with him, not his biological sister, I'm pretty sure they had sex. Let's see what the general opinion is!