回复：问单身老猫和热心人，关于老公仿冒我签名的事。

If he can forge your signature without your consent, you can tell the immigration the truth without him knowing it. Immigration will not ask you for an explanation, they will likely deny both applications on the ground you lied about your sponsorship on both cases. If you don't tell the truth, the forged signature will be deemed yours and your consent given.

Please read the responsibility of a co-sponsor, regardless of your marriage status later on, you will be responsible for your in law in case your hubby can not support her own mother.