is my boyfriend playing mind games

me and my boyfriend of 9 months had an argument the other night, things been frosty last few days we both went out last night with our friends, he never goes drinking so it didnt bother me, just this morning he texted me that he had a mad night went back to a party and got very drunk with a group of girls he knew before, he had a great time, i wrote back and said im delighted you enjoyed yourself, then he texted me that there was a girl still asleep in his house he was at work at this stage, I calmly rang him and he said to me that she was his friends gf and his friend was also there, my sister reckons hes trying to make me jealous and get a reaction off me, when i was on the phone he told me that she was a model very good looking girl,not saying im fantastic looking but im in very good shape dress v well and have been told im an attractive girl hes said it himself before that he doesnt know how he managed to get me, in the reality of it doubt any other woman would put up with the type of relationship we are in i never really see him with work and his daughter, my sister thinks i should give him the road, im 29 hes 33, he was all over me like a rash 1st 6 months now last week no kisses on texts no pet names, wondering if hes just getting comfortable now cause he knows he has me, hes already told me he loves me thanks for your help