Your ex has the right to file a case against you wherever you are if your marriage is valid. If she knows what to do, he can file bigamy case against you even if you're in the UK.
There's a certain penalty amount for those who did such.
correct, and the penalty is prison back home at least.
God grant me the serenity to accept the things i cannot change, the courage to change the things i can and the wisdom to hide the bodies of those people i had to kill because they pissed me off.