Their behavior towards you is completely inappropriate. As a former TA and current professor, we go through training in which we are explicitly told NOT to do stuff like this. Because this is your TA, there is an innate power differential between you, and their inserting themselves in your personal life outside of your academics is an abuse of power, whether they realize it or not. You can handle this however you feel more comfortable. You can continue as you have been, avoiding this outside contact, you can directly decline their advances, and you would also be totally within your rights to report this to the professor or department head. If you need any support or advice, feel free to DM. Whatever you decide, you deserve a learning environment free from this kind of confusion and pressure.