Change weights and back-propagation

[Forward process]
model_1, model_2 = Model_1(), Model_2()
model_1_weights = model_1.conv1[0].weight.data # get weights from model_1
model_2_weights = model_2.conv1[0].weight.data # get weights from model_2

new_weights = model_1_weights * 0.9 + model_2_weights * 0.1

model_1.conv1[0].weight.data = new_weights # change weights 
model_2.conv1[0].weight.data = new_weights # change weights 

model_1.forward()
model_2.forward()
...
[Backward process]
'model_1 ' only affected by 0.9 from 'new_weights'?
'model_2 ' only affected by 0.1 from 'new_weights'?
If not, how can I implement this ?