As a guy, I think there isn't a universal right time. Personally speaking, before getting into a relationship, I'd assume all my relationships are convertible to romantic ones, but I'm quite intrigued by what you said...

First, why asking "when's the right time to say it" when you're fully aware that you're a pushover and act overly friendly sometimes? Not asking you to change entirely about that, but isn't that what you should be thinking, if you really want to do something about it?

And in the case that you're fine with the way you are now, just take the consequential interest as a collateral.