Given the amount of time between entries I think you're highly unlikely to be suspected as living here on back-2-back 30 day visa exempt stamp entries.
Be advised the officers who stamp you in at passport control can always ask for the "3-proof-of's" (as it's been a real rule since 2010);
-within 30 days entering on a visa exempt entry
-within 60 days entering on a tourist visa
-hotel booking or copies of your g/f's thai house book & i/d
- proof of adequate finances
-10K baht entering on a visa exempt entry
-20K baht entering on a tourist visa or a Non-Immigrant visa
They have not enforced those requirements for a while, but more and more people are getting asked and there are even reports of people (from some countries) being denied entry when they were unable to meet those requirements.