Search Results: getting back with someone who cheated

I know many guys keep female friendships wether they are in a relationship or not just in case there is a chance with one of them.

Not all guys do that but a great number of men do this (keeping friendships for the chance of a possibility with them)

Well I am in a relationship but for some reason or another we had kept breaking up and getting back together. Now he says it's very serious and wants to make a family with me and just be serious with me.

I have one guy friend who said he would marry me, I keep in touch with him and my boyfriend does not know about him, but today it kind of slipped out into a conversation and he got mad with me and wants to know what i talk about with him and why i'm even talking to him in private chats etc. and I felt scared to I deleted and removed everything about this friend because i don't want to ruin what I have now..

but I somehow feel it's wise to still keep him around not cheating but just in case my boyfriend and i split, i have someone as possibility.. I don't like to start from scratch looking for someone and this guy could be back up

it sounds bad but really would you guys do this?
even if it sounds bad, maybe it's a smart thing to do?
I'm not going to talk or flirt with him but just keep him as contact/friend

What do you guys think?
Advice?

So me and my ex boyfriend have been together for 1year. We have both always been there for each other - doctors appointments, his surgery, he also helped me lose weight and get my drivers license. Occasionally we were having small stupid disagreements like about what I should wear, drama with his friends- he has always kept our relationship private. He was also in jail for 3 months. he was talking to me everyday saying how much he loves me and misses me and was talking to me about future plans. i was also visiting his parents house and him in jail. he knows I’m loyal to him and would never cheat on him.
Now as soon as he came out of jail, he began to act a bit differently: we were fighting more often (about what I should be wearing, my diet, and finances. 4 weeks ago he began talking to a mutual friend of ours whom recently broke up with her ex. I stayed home then he went out. So I was online after and suddenly this female tells me that she’s on a date with my man. I freaked out and was phoning her and my boyfriend then he separated with me cuz of that, yet he still has me staying over at his house cuz he wants to potentially fix things between us. He also tells me that he’s using her to show her off to our group of friends cuz he doesn’t want people to suspect that me and him were/are ever together cuz he was away for 3 months. Yet he talks to her everyday and is having sex with her and stays overnight with her on weeeknds... and he's with me during the week... he also says he doesn’t have those kinds of feelings for her and that she’s too tall for him. Now he also tells me that he prefers her in the sense that she listens to his fashion advice whereas I don’t always and she also cools him off when he’s hot whereas I don’t... he says it hurts him how someone whom he's not in love with does these things and I the girl he loves me, doesn’t... he also tells me that he would end things sooner than later with her if I show him improovements and be a “good girl”