That's still safe, but barely.
Does your charger have an automatic cut-off? most chargers, like the nitecores and the chinese-made enb-brand usb chargers all have cut-offs at 4.2v, after which it'll trickle charge around 4.2v to 4.25v (on average).
If you overcharge too often, your battery life may significantly decrease, it won't hold much of a charge, and may at some point never charge again. I've done that before, thankfully to a cheap AW cell and not an expensive sony, so learn from me and don't overcharge and over-discharge your
batteries.
