New and Old
For one thing it can be off-putting for new boyfriends. One of mine left my birthday party five minutes after meeting my ex and was never seen again.
Most blokes believe that men and women can't be just good friends - that there's always got to be something sexual to it - and with good reason: they're men.
Even if your relationship with your ex really is purely platonic, you'll have a hard job convincing your new bloke of it.
What's more, a close friendship with your ex can be very threatening for a new man, particularly in the early stages of the relationship.
The intimacy you share with your ex is a powerful reminder of the physical intimacy you once shared but, more importantly, it highlights the emotional and mental bonds - the shared history - that your new man doesn't yet have with you.
Another danger of being best friends with your ex is that it can hinder you from moving on from the relationship without you being aware of it.
If you are forever gossiping and swapping notes about your love life with your ex, subconsciously you may be measuring new or potential boyfriends against him and finding them lacking.
After all, it's hard for anyone to compete with a man you've already loved, particularly so if friendship has helped you to develop a rosy-coloured view of the relationship you had with him.
And let's not forget about sex. One of the greatest pitfalls of being too friendly with your ex is the temptation to fall into bed with him. It's just so hard to resist, especially if you are both going through a fallow period on the dating front.
There's all that latent emotion and affection between you; you've already been there before so there's no nervous embarrassment - none of the fumbling with somebody new - and he knows just what to do and how to do it.
You go out, have a good time, get a bit drunk, you're feeling randy and before you know it you're in his arms and he's in your bed again.
Uncomplicated sex with an ex is a very rare thing. It is hard to have a meaningless shag with someone that you have had a meaningful relationship with, and it is likely to stir feelings that have lain dormant or that you believed were dead.
The exception not the rule
We're not saying 'don't be friends with your ex', just be careful. Set a few boundaries and keep to them; maintain some distance between you.
Ex-boyfriends make potentially terrible best friends.
Demi Moore and Bruce Willis are an exceptional ex-couple; most exes need a little more space between them to have a healthy, happy friendship.
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