You might say to Simone that-that because the bet seemed so frivolous, or ruthless or whatever, you hadn't wanted to tell her, but there's a bet on your life.
Zera esan diezaiokezu Simoneri, ez zeniola ezer kontatu nahi izan apustuak txoro-kontua edo krudela edo dena delakoa zirudielako, baina apustua egin dutela zure biziaren gain.