Very touchy topic to me.. Need help..

Ok ladies well i'm currently 31 weeks pregnant with my daughter and last night my fiance confessed to me that he was sexting another girl but he didnt send nudes because he felt bad...? But i dont know if i could believe that ... He said that she sent him mutiple nudes and he just send muscle pictures back...? Which doesnt exactly make sense to me.. This is the message i recieved from the girl that he talked to ... I'm not sure how to react to this because hes never been this type of person... I feel disgusting and heartbroken .......... (Photo)