Can anyone say what is the current relationship status of Tony and Ziva? Are they really keeping in contact? Are they dating?
This isn't something that is currently known, as of season 12. It is assumed based on how Ziva left the show that they're still on good terms and that a future reunion is possible but whether this becomes the focus of something that occurs on screen or not is another question entirely.
To be blunt,
- They probably had sex on several occasions while on assignment. That's their business.
- They had sex at least once since Tony is the biological father of their child (S13E24).