What to do about another?

my fiancee just recently started a job and he made freinds with a female. she then added him to his facebook and started textin him. apprtly theyve also shared a kiss. and he started actin like a asshole. as were closer to our weddin date he keeps sayin he feels like hes growin up to fast and stuff. he says he still wants to marry me and thats he here with me . hes deleted his facebook when i went on it to see if there was any messages between them . and he says facebook causes too many problems becuse im jelouse over a few girls and he constantly deletes his text between the two of them so when i pick it up ill see a random one like IDK if thats a good idea it just bugs me the way he defends her about how she said shell rather quite than have him quite when i told him that i was thinkin about havin him quite. the only text i really saw was where she left her job becuse her mom was sick so now shes fired/quite? and whatever .. idk what to do really i just need some advice if im bein to jelouse or if i should worry?