fool me once, shame on you. fool me twice, shame on me.
RUN, leave. it will happen again, regardless what he says.
They both are bad. If your best friend cheats on you with your boyfriend, she is a NOT a loyal friend. And if your boyfriend cheats on you, DUMP HIM.
We would put a stop to it or leave. He is endangering your health, and clearly you can't trust him.
Are you physic?
yes but she cheats on him.
dump him
Ask him.
YES
You torture him.
shoot him in the head
it's still cheating.
Time to say goodby to your boyfriend and probably your bff, too. Why would she go out with your boyfriend if she was your best friend?