Relationship quandary

I don’t know what the right thing to do is…I have been with my partner 3 years and we are planning our future with a family etc and to all sense and purpose we are on top of the world. However I tend to get insecure a lot and find myself looking through his phone(I know it’s the cardinal sin) the first time I did this I found him chatting to a girl he went on a date with years before meeting me and arrangING to meet up with her I nipped it in the bud and he doesn’t speak to her now but he did say that if he found out id gone through his phone again he would end it…we got over that blip. But again I looked and found him chatting to someone else that I don’t know and the messages sent between them are of a sexual nature I don’t know what to do do I risk throwing away my future and say I know what was sent between them or do I let it go and get over it

You need to ask yourself why you need a man who threatens to end your relationship of 3 years if his actions cause you to feel insecure enough to go through his phone. You need to realize that you can't throw away a future if there isn't one with this man who continues to go behind your back and basically disrespect you in every way. Yes, it may be a cardinal sin to check his phone but what about his attitude towards you and your relationship together? You need a man who will go out of his way to make you feel secure, and who will support you and care for you the way you deserve to be. You really can't expect much of a future, however well planned, with a partner who you can't trust and one who's very actions should be a red flag to you.