If I subscribe to Direct Tv can I get a fios internet plan without getting fios TV?

I don't see why not

There's nothing stopping you. Verizon can't *force* you to take their TV package.

I had this exact setup about two years ago. I had DirecTV, then added FIOS internet. Verizon actually provided DirecTV as the TV service wherever FIOS TV had not been provided.

I had one bill, for internet and DirecTV. When the FIOS TV service became available, I made the change fast, but I don't think there would have been any trouble in keeping DirecTV.

Just an observation, but FIOS TV has been quite the improvement over DirecTV. Of course, I switched from SD on D* to HD on FIOS.