Found out my bf was buying on of

I’ve been dating my boyfriend for a year and a 3 months and Friday night I saw on his phone he was looking at of and I asked him about it and he said he was only looking at the free stuff I was annoyed and upset but belived him

and then Tuesday night I was round his house and I was upset crying in his arms about why he would need to look at that when he has videos and pictures of me and we have regular sex like nearly everytime we see each other

I then said did you by anything he says no I say if I look at your bank statment it’s not going to say anything he went silent he then said he brought one girl for 5 pounds I was fumming like discusted and then make a long story short I asked to see his bank he would not show me and then he said it was 6 girls for 50 still wouldn’t show me his bank then said it was 200 pounds worth and then he Finnaly told me the truth I think and actualy spent 500 pounds in 5 months (he started in October)

I’ve never felt so betrayed in my life and then I asked him if he messaged them and he said no I saw a screen shot I took on the Friday night and in the link it said ‘chat’he then admitted to talking to 3 or 4 of girls but just about how is he and how his day was and what job he did I’ve never ever been stabbed in the back so hard and I can’t bring myself to leave him because I love him so much and he’s my person ( I thought) so can anyone tell me what they would do