There's a lot to this story, so I am basically just going to bullet point.

- Been with my boyfriend for 5 months. Met at work. Was initially warned about his "player" reputation. But fell for him on day one and been with him ever since.
- He said he felt the same and had fallen for me too. Wanted to make us official, which meant giving up his manager position at work, as it was frowned upon for us to date. So I thought it was the real deal.
- Spent all of Christmas and New Year together. He met all of my family and things were perfect. He also has a 14 month old son, who I get on with great.
- Things blew up one night when we had a massive argument over something incredibly stupid, and I threatened to break up with him. He got angry about this and sent me a message saying "I've been seeing someone anyway. She's called Tasha and she's perfect. You go and be happy."
- Few days later denied everything, said he'd made her up to hurt me, and wanted me back. Foolishly I agreed.
- Spent a lot more time at his house after our argument, so decided to take a few things, deodorant, hair brushes, shampoo etc. But then started to notice strange happenings. A new brand of women's deodorant appeared in his bedroom, there were blonde hairs in my brush (I am a red-head), blonde hairs in OUR bed, female razors by the bath, and hair-ties around my brush handle (I never do this). I questioned him, and conveniently he blamed it on his younger sister, who comes and stays with him to visit her nephew.
- I wasn't convinced, and as things escalated, I decided to ask him to be honest about everything. We had a lovely evening and got really really close one night, so I asked him straight out, to which he told me the truth. That he HAD been meeting this girl, and he went to her when we rowed because he "couldn't have me". Said she'd been to his a few times, and him to her, but nothing serious. He admitted to sleeping with her, but claims this was when we had broken up (for 3 days, might I add).
- Since he told me everything, I said I wanted her gone from his life. He sent her a message explaining that he loved me, and that they were just a "fling" and that he couldn't see her again. Which set my mind at ease. Even though I can't get the thought out of my head.
- The problem NOW is that I just don't believe a word he says. Whenever he says that he can't see me tonight, because he's spending time with his son, or visiting his mother, or going out with his sister I just don't believe him. His stories never make sense. I think he is still seeing this Tasha girl, and I don't know what to do about it. He KNOWS I will ALWAYS catch him out, because he isn't smart enough- but yet he still lies to me? Am I some pathetic paranoid idiot who should learn to trust him, or is the damage already done?

I need some good advise. Its no use saying "just end it" or "its only been 5 months, walk away" because it isn't as easy as that. I really have fallen for this guy. Plus, I have bonded with his little boy, AND we work together.

I'd appreciate any help :( I don't know how to play this one.

You say you won't listen to anyone who tells you to walk away, but this man is flagrantly and blatantly cheating on you. You have two choices -- continue to be a fool or walk away.

You give your heart to a liar and cheater in 5 months? There is nothing to figure out, you remove yourself from the situation, hard choice or not. You hope to fix things that can't be fixed because he has plan B, and probably always has.

Well, you say not to tell you to just walk away.

So, I'll give you the only other advice you left as an option. That is, you are dating a cheating liar who sleeps with other women, in your bed, who then use your brush and other personal items and leave theirs behind. Your boyfriend already has a child with another women and there will be other children by other women. He is not going to change and you're not going to leave.

Given that you're not going to leave, your other option is to get used to it and stop complaining. You've decided this is the man for you - a lying cheater. Since this is your decision, you have no right to complain about him. Your parents, siblings, friends - nobody should have to hear about it because you know the problem and choose to live with it.

The solution for your problem is to leave the relationship. There is no other solution. He is an A-hole and is not going to change. We don't really care if he's charming, bought you a cute bracelet or "feels so bad" or whatever other little charming tidbits you hang onto like a liferaft to talk yourself into thinking it makes sense to stay with hin. He's also an A-hole of the first degree.

So, if you're taking that solution off the table, you might as well learn to live with and accept having an open relationship in which your boyfriend can sleep with whomever he wants, blow you off whenever he wants, and have children with whomever he wants. You can fit into his life at his convenience and accept the crumbs that are left after he feasts with other women.

You were warned before it started, know he is doing it, so what do you want people to say, you are a fool at this point, should have left long ago.