I saw a picture of my long distance boyfriend proposing to another girl and he called her the bone of his bones but he says its all a joke

Ive been with my long distance boyfriend for close to a year now and we are very close, we talk all day everyday but for the past couple of days, i had to focus on school and it made me talk to him much less, my phone was faulty so we couldnt even talk over the phone but it was just for about 3days but we talked through our email, when i got back on my phone, he started acting all funny nd suspicious and saying he had a dream about me cheating, he took it seriously but i talked him out of it playfully, then my phone tripped off again and after about two days, he said he needed a long break but i refused.. He didnt know i was gettin my phone back that day, when i came back, his bbm display picture was a picture Of him proposing to a girl who works where he works and he called her the bone of his bones .. I felt really betrayed but i decided to talk to him anyway, just to know what i did to deserve that, he said it was all just one big joke and the ring was for hia colleague who gave him for the joke , i dont know whether to believe him, as much as i love him,im not going to be anybody's side bitch. I dont know how to figure out if hes lying , the picture didnt depict a joke,it all looked so real.. He said he did it because he thought i didnt care and he thought we were on a break, he just asked for a break that same day nd he did it that day, and i hadnt even consented to the break ... Now hes apologizing but i dont know what to think

WHERE U FROM? HOW WAS UR RELATION WITH HIM SINCE A YEAR? ITS BETTER TO WAIT AND CHECK HIMTHOROUGHLY