Should i trust him?

we were together for 5 years, we were sitting together one day and i was browsing his cell phone i got sms in the inbox reading' r u free now let`s meet' and then i was surprised all i know was that he loves me to death and he started to cry for that he does`nt know the sender and he told me to call and check we made the phone on speaker and we called a girl picked it up and he asked her angrily who the hell she is , she said it was by mistake she didn`t send him i was relieved many girls used to disturb him alot and he told me also gave me his cell to keep it with me and to answer it i think he is honest......we spend many hours together after work, lunchtimes during weekends he tells me his whereabouts, and he is available anytime i call,,i say sometimes i don`t love you you have to date other girl her says i have decided with whom to be with if God`s willing you if not i will remain alone,,whenever we breakup he is the one who calls first and say i love u