Back with my husband after I cheated on him and he can't get over it...?

After having my daughter me and my husband argued as we couldn't adjust as he wanted to live the life he had before becoming a dad and our life was non existant. he is 42 and i'm 26 so there's an age gap and he has a complex about it. Three years later and I had enough and I slept with an ex work colleague a few times which i'm now utterly ashamed off. I moved in with him but things didn't work out and we broke up. i lived on my own for a year but started dating my husband again and we got back together. i told him that i was a tramp for doing what i did and that i was in a bad place then and wouldnt ever cheat again. we have been getting on fine and took my daughter to miami for a vacation. While on the beach in my bikini some guy wolf whistled and asked me if i needed any lotion rubbed on my body. i said no thanks but my hubby accused me of flirting with him. he cant get over it and he told me that he always imagines my old work colleague rolling around with me naked and it makes him sick. because he is a lot older he has a real complex and i love him and have made a real effort in bed. he banned me from wearing bikinis on vacation. how do i get him to get over this ? i want to be with him and want another baby with him. just because i have been naked with another guy on a moment of madness shouldn't change anything ?