Just bought my 1st home. On/Off Boyfriend lives w/me in Texas. Common law applies?? How do I protect my home??

My ex and I have been together for 4 years on and off. when we are together, we have shared an apartment. He does get magazines mailed to him but apartments have ALWAYS been in MY name alone. He's not even listed as an occupant. On our latest split, I bought my 1st home. We have maintained contact and he's trying to come back. he still thinks I'm ';renting'; the home rather than buying. In texas, how do common law marriage issues apply to me? How can I protect my home in the event we get back together/split again? Does he have rights to MY home? Help! BTW, Common law marriage is considered after 6 months co-habitation in Texas. Thanks!